Free Essay

Bonding Essay

In: Other Topics

Submitted By JEYDI
Words 3332
Pages 14
Pure chemical substances are classified as ionic, metallic, covalent molecular and covalent network. In this essay I will describe the nature of each bonding present in these different types of substances and use this to explain the physical properties they exhibit and their structures.
Ionic compounds are compounds that are composed of positive and negative ions. An ionic compound is a chemical compound in which ions are held together in a lattice structure by ionic bonds. Usually, the positively charged portion consists of metal (cations) and the negatively charged portion is an (anion) or polyatomic ion. Ions in ionic compounds are held together by the electrostatic forces between oppositely charged bodies.

The positive and negative ions in these compounds are thought to be arranged in an orderly three-dimensional lattice. For example, the structure of sodium chloride is shown. In the lattice, each positive sodium ion is surrounded by six negative chloride ions and each negative chloride ion is surrounded by six positive sodium ions. The position of the ions is fixed and apart from vibration about these fixed positions no other movement of the ions occurs in the solid compound.

Each ion in an ionic solid is held in the crystal lattice by strong electrostatic attractions to the oppositely charged ions around it. These electrostatic forces between the positive and negative ions are called ionic bonds. Because ionic compounds have high melting points, in other words considerable energy is required to disrupt the attractive forces between the positive and negative ions; ionic bonding is regarded as an example of strong bonding. It’s also a bond in which on atom loses an electron to form a positive ion (cation) and the other atom gains an electron in order to have a full outer shell of electrons to make them stable. One atom pulls an electron from another atom.

For example in sodium chloride, sodium loses one electron to form a sodium ion, electron is not loss but transferred to chlorine to form chlorine ion. They are oppositely charged ions and will be electrostatically attracted to one another. This electrostatic attraction is an ionic bond. Sodium chloride (NaCl) then represents ionic compound because it is held intact by ionic bond.

Another example is magnesium oxide; magnesium transfers its covalent electrons to oxygen forming the magnesium ion and an oxide ion. Then, the resulting ion is electrostatically attracted to one another forming an ionic bond.

Calcium loses two electrons to form a calcium ion, one of these electrons is transferred to chlorine atom and another is transferred to another chlorine atom forming two chloride ions. The calcium ion is electrostatically attracted to the two chloride ions because the opposite charges must fully balance each other up in all three examples, the resulting ionic compound have an overall neutral charges because all charges are full balance out.

In summary an ionic bond is defined as the electrostatic attraction between oppositely charged ions, when an ionic compound is formed the charges must be balance so that the resulting ionic compound has an overall neutral charge.

As with metals there are variations in the properties of individual ionic compounds, but some generalisations can be made about the physical properties characteristic of ionic compounds. Ionic compounds have high melting and boiling points and are all solids at room temperature. They are made up of hard crystals and they are neither malleable nor ductile, but are brittle. In the solid state they are non-conductors of electricity but they are good conductors of electricity in the liquid state. The solutions formed from soluble ionic compounds are good conductors of electricity. Their solubilities in water vary from very soluble to insoluble. They are not soluble in non-polar solvents, such as oil. Ionic solids formed from group 1 and 2 metals are white or colourless while those formed from transition metals are usually coloured The strong, electrostatic attractions between the oppositely charged ions in the three-dimensional lattice result in ionic solids being hard and difficult to cut. The brittleness of ionic compound results from the orderly arrangement of ions in a crystal being disturbed after a layer of ions is forced to slide past another layer. Because of the displacement, ions of similar charge are forced closer to one another with an increase in repulsive forces and a decrease in attractive forces. As a result, the crystal will shatter. The forces of attraction between the oppositely charged ions in ionic compounds are so strong that large quantities of heat energy must be supplied to disrupt the crystal lattice and separate the ions. Consequently, ionic solids have high melting points. In the liquid state, the ions have sufficient energy to move around randomly, but they are still close together. As a result, the attractive forces between the positive and negative ions in the liquid state are still strong. These attractive forces will be broken when the ionic compound boils to form a gas. In other words, molten ionic compounds have high boiling points (even though many decompose before they reach their boiling temperatures). When a soluble ionic compound is added to water, the ions break away from the ionic lattice and mix with the water molecules.

If an insoluble ionic compound is added to water, the ions essentially remain bonded together in the ionic lattice. There is no simple explanation for why some ionic compounds are soluble and others are insoluble in water.
Ionic solids do not conduct electricity because, although they contain charged particles, these ions occupy fixed positions and are not free to move through the solid lattice. Molten ionic compounds do conduct electricity because in the molten state the positive and negative ions are no longer strongly bonded in fixed positions in a lattice but are able to move through the liquid. Although molten ionic compounds conduct an electric current, they do not conduct as well as metals. This suggests that electrons in metals are much more mobile than ions in the molten state.
Covalent bonding is a chemical bond that involves sharing a pair of electrons between atoms in a molecule. The two atoms have positive nuclei. They are both attracted to the same electron. In this way the two nuclei are held close to each other. Each atom will follow the octet rule – A full outer shell (of 8 electrons). In some cases this may involve sharing 4 electrons (a double bond) or 6 electrons (a triple bond).

For example in the hydrogen molecule, the shared pair of electrons would be in the region between the two nuclei most of the time, that is, there is a greater probability of finding the bonding electrons in this region. The density of the electron cloud is therefore greater between the two nuclei in the molecule. The two positively charged nuclei are held together by their mutual attraction to the two shared electrons, or in other words, they are held together by a covalent bond. Because the hydrogen molecule is stable, the electrostatic attractive forces between the two positive nuclei and the shared electrons must balance the repulsive forces between the nuclei and between the electrons. The attractive forces between the nuclei and shared electrons balance the repulsive forces between the nuclei and between the electrons in the stable hydrogen molecule. Covalent bond formation in a hydrogen molecule can also be illustrated using the Bohr-model representation of atoms and electron dot diagrams.

A covalent bond in which 2 electrons are shared is called a single covalent bond and it can be represented by a line drawn between the atoms. Hence a hydrogen molecule can be represented as H–H. Another example is when two chlorine atoms, with electron configurations of 2, 8, 7, combine to form a chlorine molecule, the chlorine atoms share a pair of electrons. In this way, each chlorine atom obtains a share in 8 valence electrons and acquires the electron configuration of the noble gas argon. As with ionic compounds, the octet rule is ‘obeyed’ in many covalent molecular substances.

The two chlorine atoms in the molecule are held together by the attractive forces between their nuclei and the pair of shared electrons. That is, there is a single covalent bond between the atoms in the Cl2 molecule. In the chlorine molecule, 2 electrons are shared, but the other valence electrons are not involved in the bonding. The electron pairs forming covalent bonds in molecules are called bonding electron pairs. The remaining valence electron pairs, if any, are called non-bonding electron pairs or lone pairs. The one bonding pair and six non-bonding pairs of valence electrons in a chlorine molecule are shown below.

Here are some examples of electron dot diagram:
Experimental evidence indicates that covalent molecular substances consist of neutral molecules. As defined earlier, a molecule is a group of two or more atoms held together by covalent bonds. For a covalent molecular substance in the solid state, the neutral molecules are organised in an orderly lattice structure. In the liquid and gas states, the molecules are arranged randomly. In the gas state, however, the molecules are much further apart from each other than in the liquid state. It made up of discrete molecules. The forces that hold the molecules together are comparatively weak and the strength of the covalent bond is very strong.

Substances made up of molecules have the following properties in common. Covalent molecular have low melting and boiling points and many are liquids or gases at room temperature. They are non-conductors of electricity in both the solid and liquid states and the aqueous solutions of some compounds are weak conductors of electricity however few compounds in aqueous solution are good conductors of electricity. Covalent molecular form solids that are generally quite soft are easily scratched and often have a waxy appearance. Many solids are malleable when bent and do not shatter when hit. And many are insoluble in water, but are soluble in non-polar solvents such as petrol and kerosene. Also many have an odour.
Generally, the attractive forces between the molecules of covalent molecular substances are weak, as indicated by the low melting points of these substances. For example, ice has the low melting point of 0°C because the attractive forces between the water molecules, the intermolecular forces, are relatively weak. However, a large amount of energy is required to break up water molecules into individual hydrogen and oxygen atoms. For the process H2O(g) → 2H(g) 1 O(g) to occur to a significant extent, a temperature of over 2000°C is required. This indicates that the covalent bonds between the hydrogen and oxygen atoms within water molecules must be strong. As with melting, when a covalent molecular substance is boiled, it is the weak intermolecular forces between the molecules that are disrupted, not the covalent bonds between the atoms in the molecules.
Covalent molecular solids such as wax, chocolate and butter are soft and can be cut easily. As with the low melting and boiling points, this property can also be explained in terms of the weak attractive forces between the molecules. Very little force is required to push the neutral molecules in the solid lattice past one another. Even with ice, which is possibly one of the harder molecular substances, it can be crushed fairly easily, compared with, for example, the ionic substance marble and the metal steel.
Many covalent molecular substances, particularly those made up of larger molecules such as petroleum jelly and some of the plastic materials, can be bent or pushed into another shape without the solid shattering. When a force is exerted on a molecular substance, the molecules can be pushed past one another easily because of the weak forces between them. But once the molecules reach their new positions, weak forces still exist between them and they remain held together in the new shape.
No charged particles exist. The molecules are neutral. As a result in an electrical current cannot be carried. Covalent molecular acids are the exception. They form ions when they are dissolved in water which is able to conduct electricity (like an ionic solution). For a substance to conduct electricity, mobile charged particles capable of conducting electricity must be present. These charged particles include electrons and positive and negative ions. In covalent molecular substances, there are no ions because the molecules are neutral. Also, in the molecules the valence electrons are localised between or around atoms, as either shared or unshared pairs, and so are not free to move throughout the solid lattice or the liquid. As a result, covalent molecular substances are non-conductors of electricity in the solid and liquid states. When dissolved in water some covalent molecular substances conduct electricity. These substances form or break up into ions (ionise) when added to water. The mobile ions in the aqueous solutions are then able to act as the charge carriers of the electric current.
The solubility properties of covalent molecular compounds vary considerably. Some are very soluble in water, others slightly soluble, but many are insoluble. For example, ethanol and sugar are soluble in water but butter, chocolate and olive oil is insoluble in water. Numerous covalent molecular substances are soluble in non-polar solvents such as oil and kerosene. For example, cooking oil and petrol are soluble in kerosene.

Metallic bonding refers to the interaction between the delocalised electrons and the metal nuclei. The physical properties of metals are the result of the delocalisation of the electrons involved in metallic bonding. Chemists have developed various models to explain the characteristic properties of metals. In one of these models, it is assumed that the outermost or valence electrons of metal atoms move about freely within a three-dimensional arrangement or lattice of positively charged metal ions. That is, the metal consists of a lattice of positive ions surrounded by a ‘sea’ of mobile electrons. The valence electrons are said to be delocalised as they are not associated with a particular metal ion but can move freely through the lattice of metal ions. The positively charged metal ions in the lattice are attracted to the negatively charged delocalised electrons and these electrostatic attractions hold the metallic lattice together. This type of bonding, that is, the electrostatic attractions between the delocalised electrons and the positive metal ions, is called metallic bonding.

Solid metals are good conductors of electricity in both the solid and liquid states. In the solid state, conductivity decreases with increasing temperature. Metals are good conductors of heat in both the solid and liquid states. As a consequence, the solid metals feel cold to touch. Metals are also lustrous (shiny) when freshly cut or cleaned. Metals are malleable (can be hammered or pressed out of shape without breaking) and ductile (able to be drawn into a wire). They are hard, tough and dense at room temperature. Silver in colour (except for copper and gold). Mostly high melting points (there is a great variety within this property though). Sonorous, make a pleasant ringing tone when tapped (if manufactured as a shape that is allowed to vibrate).
The ‘electron sea’ model of metallic bonding can be used to explain the common properties of metals. Metals are good conductors of electricity because of the mobility of the delocalised electrons within the lattice of positive ions. When a metal is used in an electrical circuit, electrons entering one end of the metal cause a similar number of electrons to be displaced from the other end, and the metal conduct. In the solid state, the positive ions do not act as charge carriers. They remain vibrating about fixed positions within the lattice, as the delocalised electron move. However, when a molten metal conducts electricity, both the delocalised electrons and the positive ions are able to move and act as charge carriers.

The delocalised electrons are also responsible for the rapid transmission of heat energy in metals. When one end of a piece of metal is heated, the kinetic energy of the positive ions and the delocalised electrons in the heated region increases, that is, their rate of movement increases. The heat energy is conducted along the piece of metal by the more energetic electrons and positive ions colliding with less energetic electrons and ions. However, because the electrons are delocalised, they are able to move quite freely through the lattice and so cause a transfer of the heat energy along the metal that is more rapid than for most other materials.
The delocalised electrons in metals do not ‘belong’ to any particular positive ion in the lattice, so metallic bonding is said to be non-directional. Therefore, if sufficient force is applied to the metal, one layer of positive ions can slide, or slip, over another without disrupting the metallic bonding. This means that, after the layer of positive ions has moved, there are still attractive forces between the delocalised electrons and the positive ions holding the lattice together in the newly deformed metal. As a result, metals can be hammered readily into sheets or drawn into wires without breaking.

The relatively high melting and boiling points of most metals are due to the strong electrostatic attraction between the positive metal ions and the delocalised electrons. The stronger the metallic bonds, the greater the amount of heat required to move the ions out of their fixed positions, that is, the higher the melting point. It takes a large amount of heat energy to disrupt these forces. Melting points tend to increase across a period. This is partly due to the number of valence electrons increasing – meaning there will be more delocalised electrons as you go across the table and therefore stronger bonding forces.

Most substances formed when non-metal atoms combine are covalent molecular substances. That is, substances in which the atoms are covalently bonded in small groups called molecules. However, a few non-metallic substances have quite different properties compared with those of covalent molecular substances. For example, both carbon and silicon, which are group 14 elements, form oxides with formulas of CO2 and SiO2 respectively, yet the physical properties of these two compounds, are somewhat different. An exception to the rule – where covalent substances usually form discrete molecules. In these few cases these substances form a lattice or network of covalent bonds. Examples include silicon dioxide, carbon (graphite, diamond and fullerenes).
Covalent network substances have a very high melting and boiling points. It is non-conductors of electricity in the solid and liquid states and it’s extremely hard and brittle. Covalent network is reasonably chemically inert and insoluble in water and most other solvents. Covalent network substances have very high melting points and are very hard because each atom is held in the rigid lattice by the strong covalent bonds. To break these bonds requires a very large amount of energy. However, if some of the covalent bonds are broken, the network lattice is placed under stress and rather than it changing shape or becoming distorted, the solid shatters. In a covalent network substance, the electrons are either inner-shell electrons or localised in the bonding and non-bonding pairs around each atom. As a result, these electrons cannot act as charge carriers in the conduction of electricity. There are also no ions present in the lattice. It therefore follows that pure substances, with atoms covalently bonded in a three-dimensional lattice, are not expected to be conductors of electricity.
As there are no charged particles free to move – covalent network substances cannot conduct electricity Graphite is the exception. Each carbon atom has 3 bonds to another carbon all in the same plane. The fourth exists in between two layers of this planar formation – holding the layers together. These electrons are free to move and can thus conduct electricity.

Silicon Dioxide




In conclusion, we talked about the different properties, structures and the bonding of metallic compound, ionic compound, covalent network and covalent molecular.

Similar Documents

Free Essay

Dont Use This

...polar bond | c. | structural formula | f. | hydrogen bond | ____ 1. a depiction of the arrangement of atoms in molecules and polyatomic ions ____ 2. a covalent bond in which only one pair of electrons is shared ____ 3. a covalent bond in which two pairs of electrons are shared ____ 4. a covalent bond in which the shared electron pair comes from only one of the atoms ____ 5. a covalent bond between two atoms of significantly different electronegativities ____ 6. a type of bond that is very important in determining the properties of water and of important biological molecules such as proteins and DNA Match each item with the correct statement below. a. | network solid | e. | tetrahedral angle | b. | bonding orbital | f. | VSEPR theory | c. | dipole interaction | g. | sigma bond | d. | bond dissociation energy | ____ 7. energy needed to break a single bond between two covalently bonded atoms ____ 8. symmetrical bond along the axis between the two nuclei ____ 9. molecular orbital that can be occupied by two electrons of a covalent bond ____ 10. 109.5 ____ 11. shapes adjust so valence-electron pairs are as far apart as possible ____ 12. attraction between polar molecules ____ 13. crystal in which all the atoms are covalently bonded to each other Multiple Choice Identify the choice that best completes the statement or answers the question. ____ 14. What information does a molecular formula......

Words: 5916 - Pages: 24

Free Essay

An Essay on Marshmallow

...An essay on marshmallow I shall now enrich your life by sharing with you about marshmallow. Many an afternoon has been enjoyed by a family, bonding over the discussion of marshmallow. Cited by many as the single most important influence on post modern micro eco compartmentalism, it is impossible to overestimate its impact on modern thought. Since it was first compared to antidisestablishmentarianism much has been said concerning marshmallow by so called 'babies', many of whom blame the influence of television. Keeping all of this in mind, in this essay I will examine the major issues. Social Factors Society begins and ends with marshmallow. When Sir Bernard Chivilary said 'hounds will feast on society' [1] he globalised an issue which had remained buried in the hearts of our ancestors for centuries. Spanning divides such as class, race and uglyness, marshmallow bravely illustrates what we are most afraid of, what we all know deep down in our hearts. Our post-literate society, more than ever before, relies upon marshmallow. To put it simply, people like marshmallow. Economic Factors Derived from 'oikonomikos,' which means skilled in household management, the word economics is synonymous with marshmallow. Of course, marshmallow fits perfectly into the Inter-Spam model. Taking special care to highlight the role of marshmallow within the vast framework which this provides. |National |[pic] | |Debt | | ...

Words: 465 - Pages: 2

Free Essay

Formal Report Format

...the transfer of electrons. _____________________________________________________________________________________ Introduction The atoms in a compound are held together by a chemical bond. There are two types of chemical bond: ionic and covalent bond. An ionic or electrovalent bond results from the electrostatic attraction between metal and non-metal atoms by the transfer of electrons. One example is the formation of bond between a sodium metal atom and a chlorine non-metal atom [1]. In contrast, covalent bond involves the sharing of valence electrons between non-metal atoms. A covalent bond becomes polar when there is unequal sharing of bonding electrons. This happens when the elements involved in the bond has a significant difference in their electronegativity, such as in hydrochloric acid, HCl. Equal distribution of bonding electrons leads to the formation of a non-polar covalent bond. This happens when there is small or no difference in electronegativity between the atoms in a bond. Chlorine gas, Cl2, has a non-polar covalent bond. Electrical conductivity, the flow of electric current, can be used as a basis for determining the type of chemical bond present in a compound. An ionic compound, when dissolved in an aqueous solution, conducts electricity because it contains...

Words: 761 - Pages: 4

Premium Essay

Unit 7 Chapter 8 Study Guide

...Unit 7 Unit 8 Study Guide 1. Which of the following statements is incorrect? A) Ionic bonding results from the transfer of electrons from one atom to another. B) Dipole moments result from the unequal distribution of electrons in a molecule. C) The electrons in a polar bond are found nearer to the more electronegative element. D) A molecule with very polar bonds can be nonpolar. E) Linear molecules cannot have a net dipole moment. 2. Atoms having greatly differing electronegativities are expected to form: A) no bonds B) polar covalent bonds C) nonpolar covalent bonds D) ionic bonds E) covalent bonds 3. Choose the compound with the most ionic bond. A) LiCl B) KF C) NaCl D) LiF E) KCl 4. Atoms with very similar electronegativity values are expected to form A) no bonds. B) covalent bonds. C) triple bonds. D) ionic bonds. E) none of these 5. Which of the following bonds is least polar? A) C—O B) H—C C) S—Cl D) Br—Br E) They are all nonpolar. 6. For the elements Rb, F, and O, the order of increasing electronegativity is: A) Rb < F < O B) Rb < O < F C) O < F < Rb D) F < Rb < O E) None of these 7. For the elements Cs, F, and Cl, the order of increasing electronegativity is: A) F < Cl < Cs B) Cs < Cl < F C) Cl < Cs < F D) F <......

Words: 3943 - Pages: 16

Premium Essay

Stages of Interpersonal Relationships

...Phases of Interpersonal Relationship Development A relationship is the way in which two or more concepts, objects, or people are connected, or the state of being connected. It involves building and maintaining a bond of trust and transparency. The development of interpersonal relationship involves the initiation, development and maintenance of the relationship. The ability to identify and control the deterioration of the relationship will determine whether the relationship will continue or end on a negative note. A relationship goes through six stages that will ultimately end up in one of two endings, repairing stage or dissolution stage. They are: * Contact- When people first meet, the first perceptual reaction is to evaluate the other person and decide whether or not to engage. This takes place in a matter of seconds and is an involuntary response related to our "fight or flight" instincts. * Involvement- At the second stage, individuals disclose information about themselves and engage in deeper conversations. The involvement process may also include testing to see if the other person is ready to commit to the next level or if it is better to leave things as they are and not bother developing the relationship further. * Intimacy- A relationship is at its deepest and most committed level. Individuals self-disclose and the commitment moves into the public forum. Changing minds occur in this stage. This involves such demonstrations as getting married or......

Words: 942 - Pages: 4

Free Essay

Investigation of Action of Saliva and Hydrochloric Acid in Carbohydrate Solution

...Chapter 8 Covalent Bonding and Molecular Structure Chapter 8: Covalent Molecular Structure Bonding and Chapter In Context In this chapter and the next, we examine chemical bonding in detail. We examined ionic bonding briefly in Chapter 2 and will do so in more detail in Chapter 11. We will also examine intermolecular forces in detail in Chapter 11. Here we will apply what you have learned about atomic structure (Chapter 6), electron configurations, and periodic trends (Chapter 7) to the chemical bonds formed between atoms and ions and the shapes of molecules and ions that contain covalent bonds. • 8-1 Biology: Molecular shape of enzymes specifically allow only certain reactions to occur. Drugs are developed that specifically fit into active sites in the enzyme to affect or even stop its action. Chapter 8 8.1 Interactions Between Particles: Coulomb’s Law 8.2 Covalent Bonding Basics 8.3 Lewis Structures 8.4 Bond Properties 8.5 Electron Distribution in Molecules 8.6 Valence-Shell Electron-Pair Repulsion Theory and Molecular Shape 8.7 Molecular Polarity Chapter Goals • Apply Coulomb’s Law. • Understand forces involved in covalent bonding. • Write Lewis symbols and Lewis structures. • Predict bond properties. • Understand charge distribution in molecules. • Use VSEPR theory. • Identify polar and nopolar species. Chapter 8 Covalent Bonding and Molecular Structure 8-2 8.1 Interactions Between Particles: Coulomb’s Law OWL Opening Exploration 8.1 Coulomb’s Law Matter is...

Words: 8991 - Pages: 36

Premium Essay

The Truth About Male Friendship

...The truth about male friendship ‘’For men to really become friends there has to be an element of adventure.’’ Michael Chabon says this in his Pulitzer prize-winning The Amazing Adventures of Kavalier and Clay, and it is the basic line in male friendship. The thing that happens with men when they are in each other’s company is the very idea of adventure. It doesn’t have to a big adventure, as long as the two of you makes it big. Safraz Manzoor has taken it upon his shoulders, to describe this phenomenon in the text, ‘‘The truth about male friendship’’. In the text we are introduced to the man Safraz Manzoor, the writer of the text, and his all-time best friend Amolak, who is a banker. He tells us about how he and Amolak shares different passions, among them music, which is known as a great way to bond, not just with your friends, but with anybody. Safraz and Amolak have been friends since they were 16, so 25 years of friendship by the time that Safraz wrote the text. This doesn’t mean 25 years of a happy friendship with cake and flowers, which isn’t the case in many long-running male friendships. My father has this friend called Søren. They shared the most of their teenage years with each other, and were inseparable until the age of 23. What happened here was Søren’s girlfriend, drunk as she was, asking my father for a kiss, and, drunk as he was, he said yes. Søren quickly knocked out my father, still has a scar under his beard, and they didn’t talk to each other......

Words: 918 - Pages: 4

Premium Essay


...between an ion and a neutral polar molecule which possess a dipole moment. Polar molecules are dipoles; they have a positive end and a negative end. The positive ions are attracted to the negative end of a dipole, while negative ions are attracted to the positive end. An example of ion-dipole interaction is K+ ---H2O d. Dispersion forces (London forces): London forces are weak intermolecular forces that arise from temporary multi-pole interactive forces between molecules without permanent multi-pole moment. A good example of London forces is CH4 (methane). e. Van der Waals forces: Van der Waals force is the attractive or repulsive force between molecules (or between parts of the same molecule) other than those due to covalent bonding or electrostatic interaction of...

Words: 2850 - Pages: 12

Free Essay

Ergonomic Case Study

...Malayan Colleges Laguna S.Y 2012-2013 Fastech Synergy Philippines Incorporated Ergonomic Case Study In Partial Fulfilment of the Requirements for the Course Ergonomics (IE115) Submitted by: Buenflor, Mary Abigail L. Cacayan, Gellie L. Nagpala, Ivan Jesrael E. Pablo, Mark Joseph E. Ramos, Charisse Joyce N. Submitted to: Prof. Ezrha C. Godilano IE115 – B31 December 3, 2012 INTRODUCTION Established in 1983, Fastech is one of the leading providers of assembly and test services to the semiconductor integrated device manufacturers (IDM) in USA, Europe, and Asia. This company was formerly known as Circuit Packaging, Inc. and changed its name to Fastech Synergy, Ltd. in 1989. This is a Filipino-owned company and managed by Mr. Saturnino G. Belen, Jr., the current Chairman and Chief Executive Officer of the group. In 1992, Fastech has established a manufacturing site located in Light Industry and Science Park I, Cabuyao, Laguna, Philippines. Fastech Synergy Ltd. offers a complete range of manufacturing capabilities including the full spectrum of RF and microwave testing and tuning. It is positioned to meet high demand for semiconductor and microwave manufacturing services for applications in the field of computers, telecommunications, consumer and automotive products. Fastech Synergy has currently 359 employees consisting of 125 males and 234 females. It operates in three shifts: Shift A (6am – 2pm), Shift B (2pm – 10pm) and Shift C (6am – 6pm). Office......

Words: 2059 - Pages: 9

Premium Essay

Social and Behavior Paper

...During the early months of a growing infant, there is an opportunity for optimal attachment to the mother or both parents. This is a crucial time for the baby, during this time the infant will attachment to its parents and forms either a secure attachment, insecure avoidance attachment or insecure ambivalent attachment. Attachment is considered a social concept in childhood development because; it lays the foundation for relationships with parents, siblings, friends and relatives. It also effects whether or not the child will grow up with the ability to hold fulfilling and successful relationships. When a child grows up with a secure attachment to both parents, they tend to have great problem solving skills as well as social skills. It also provides the starting point for the child to grow into a secure individual capable of have strong and stable emotional bonds with others. There are three attachment qualities in the developing child; secure attachment, insecure avoidance and insecure ambivalent attachment. When a child is securely attached to the parent they have a stable emotional bond with the parent. They are upset with the parent leaves however they experience a smaller amount of separation anxiety than the others. Also when the parent returns, the child actively seeks to be near the parent once again. Insecure avoidance attachment is just the opposite; they have anxious emotional bond with the parent and tend to shy away from the parent when he/she returns. A......

Words: 515 - Pages: 3

Free Essay

Organic Chemistry Note

...Organic Chemistry Second Edition The INSTANT NOTES series Series Editor: B.D. Hames School of Biochemistry and Molecular Biology, University of Leeds, Leeds, UK Animal Biology 2nd edition Biochemistry 2nd edition Bioinformatics Chemistry for Biologists 2nd edition Developmental Biology Ecology 2nd edition Immunology 2nd edition Genetics 2nd edition Microbiology 2nd edition Molecular Biology 2nd edition Neuroscience Plant Biology Chemistry series Consulting Editor: Howard Stanbury Analytical Chemistry Inorganic Chemistry 2nd edition Medicinal Chemistry Organic Chemistry 2nd edition Physical Chemistry Psychology series Sub-series Editor: Hugh Wagner Dept of Psychology, University of Central Lancashire, Preston, UK Psychology Forthcoming titles Cognitive Psychology Physiological Psychology Organic Chemistry Second Edition G. L. Patrick Department of Chemistry and Chemical Engineering, Paisley University, Paisley, Scotland This edition published in the Taylor & Francis e-Library, 2005. "To purchase your own copy of this or any of Taylor & Francis or Routledge's collection of thousands of eBooks please go to www.eBookstore.” © Garland Science/BIOS Scientific Publishers, 2004 First published 2000 Second edition published 2004 All rights reserved. No part of this book may be reproduced or transmitted, in any form or by any means, without permission. A CIP catalogue record for this book is available from the British Library. ISBN 0-203-42761-0 Master......

Words: 119372 - Pages: 478

Free Essay

I Cannot Live with You

...I Cannot Live With You The poem “I Cannot Live with You” talks about a relationship that can’t be. How they can’t live together or die together because they are so different. This poem actually hits really close to home. A few months ago I was in a relationship where I just couldn’t live with someone. It all started in June during Badger Connection. That’s where I met Brittany Dyson. We spent the entire day together where we really learned a lot about each other. Brittany is from New Orleans, Louisiana where she graduated top of her class. We left Badger Connection being really good friends. We kept in contact over the rest of the break. Once school started we were right back where we started. We hung out a lot during the first week of school. Everyone thought that we were dating because we spent so much time together. We were not dating. One night we were sitting in the lobby in Toolen Hall watching “House M.D,” and she leans over and kisses me. It got so awkward that she left Toolen and I didn’t see her for two days. During those two days I started to think about our friendship and the kiss just kept playing over and over inside of my head. When I finally saw her again it was still pretty awkward between us, but I swallowed it and just talked to her. I told her that I had feelings for her and she told me the same. That day we decided to date. Dating lasted all of three days, then we decided to become official. Our friends were relived because it killed all of the......

Words: 1107 - Pages: 5

Free Essay

Chem 1

...reactions, the properties of synthetic material, or the intricate life-sustaining processes of living cells, molecular shape is a crucial factor. 10.1 Depicting Molecules and Ions with Lewis Structures Lewis structures, also called electron-dot structures or electron-dot diagrams, are diagrams that show the bonding between atoms of a molecule, and the lone pairs of electrons that may exist in the molecule. A Lewis structure can be drawn for any covalently-bonded molecule, as well as coordination compounds. Using the Octet Rule to Write Lewis Structures The octet rule tells us that all atoms want eight valence electrons (except for hydrogen, which wants only two), so they can be like the nearest noble gas. Use the octet rule to figure out how many electrons each atom in the molecule should have, and add them up. The only weird element is boron - it wants six electrons. Lewis Structures for Molecules with Single Bonds The atoms share a pair of electrons, and that pair is referred to as a bonding pair. The pairs of electrons which do not participate in the bond have traditionally been called "lone pairs". A single bond can be represented by the two dots of the bonding pair, or by a single line which represents that pair. The single line representation for a bond is commonly used in drawing Lewis structures for molecules. · Hydrogen atoms form one bond. · Carbon atoms four bonds. · Nitrogen atoms form three bonds. · Oxygen atoms form two......

Words: 2714 - Pages: 11

Premium Essay


...SCH4U – The Chemistry of Covalent Bonding Date_____________________ Orbital Hybridization One of the most influential chemistry books ever written was The Nature of the Chemical Bond by Linus Pauling (1901-1994). Published in 1939, Pauling was awarded the Nobel Prize in 1954. Pauling received a second Nobel Prize for peace in 1962. Pauling made tremendous contributions to the field of chemistry, and was an outspoken activist against war and nuclear weapons. If you consider the energy level diagram for carbon it presents a problem to the VB theory. If bonds are formed between orbitals that contain unpaired electrons, how many bonds does it appear carbon can form? | | 2 | | 1 | | Since Carbon only has 4 different 4 valence electrons, according to the Aufbau principle, the 2s orbital is filled first, and then the 2p sub shell has 2 orbitals with unpaired electrons. This suggests that Carbon can only form 2 bonds. However Carbon is clearly able to form 4 bonds, as evidenced by any carbon compound (e.g. methane, CH4). Linus Pauling suggested that carbon is able to create four unpaired orbitals by promoting one electron from the 2s orbital to the empty 2pz orbital. This hybridizes the one 2s and three 2p orbitals together. This configuration is called ‘sp3’. Like s and p orbitals, the ‘shape’ of sp3 orbitals can be defined by a probability density map of electron location around the nucleus. The shape of a sp3 orbital looks like this: Since......

Words: 1840 - Pages: 8

Premium Essay

Chemistry Solubility

...Jacinta Houng Comparing the Solubility of Chemicals in Water “Water is known as the “universal solvent” because so many different substances dissolve in it and we rely on this for many of our daily needs.” Introduction: Water is known as the ‘universal solvent’ as it is capable of dissolving a variety of different substances and dissolves more substances than any other liquid. However the ability to be soluble depends on a substances polarity and bonding. This then contributes to the various ways that different types of chemicals interact in water. Solubility is crucial to every living thing on earth as water can carry along valuable chemicals, minerals, and nutrients necessary for survival. In fact Water covers 70% of the Earths surface and composes 55-70% of the human body. Water is an excellent solvent due to its chemical composition and physical attributes. According to USGS ( ) Water molecules have a polar arrangement of the oxygen and hydrogen atoms—one side (hydrogen) has a positive electrical charge and the other side (oxygen) has a negative charge. A polar bond is a covalent bond between two atoms where the electrons forming the bond are unequally distributed. This causes the molecule to have a slight electrical dipole moment where one end is slightly positive and the other is slightly negative. "Like dissolves like" is an expression used by chemists to help them remember how solvents work. The expression refers to...

Words: 3033 - Pages: 13