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Mitosis

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1. Atom
The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons

Atoms are made up of three basic particles:
Protons-carries a positive charge
Neutrons-carry no charge
Electrons-carry a negative charge and encircles the nucleus.
(http://education.jlab.org/atomtour/listofparticles.html)
2. Element
A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. http://en.wikipedia.org/wiki/Chemical_element 3. Compound
A chemical compound is a pure chemical substance consisting of two or more differentchemical elements[1][2][3] that can be separated into simpler substances by chemical reactions.[4] Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms[3] that are held together in a defined spatial arrangement bychemical bonds. Chemical compounds can be molecular compounds held together bycovalent bonds http://en.wikipedia.org/wiki/Chemical_compound 4. Mass number
The mass number (A), also called atomic mass number or nucleon number, is the total number of protons and neutrons (together known as nucleons) in an atomic nucleus. http://en.wikipedia.org/wiki/Mass_number 5. atomic number the atomic number (also known as the proton number) is the number of protons found in the nucleus of an atom and therefore identical to the charge number of the nucleus http://en.wikipedia.org/wiki/Atomic_number 6. octet rule
The octet rule is a chemical rule of thumb that states that atoms of low (<20) atomic number tend to combine in such a way that they each have eight electrons in their valence shells, giving them the same electronic configuration as a noble gas. The rule is applicable to the main-group elements, especially carbon, nitrogen,...

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