ELEMENT: a substance that cannot be broken down to other substances by chemical reactions.

COMPOUND: a substance consisting of two or more elements combined in a fixed ratio.

MOLECULE: two or more atoms held together by covalent bonds

TRACE ELEMENTS: those required by an organism in only minute quantities.

Give the mass, charge, and location of each sub-atomic particle.

Mass= 1 Dalton or 1.009 grams or 1.7 x 10-24

Mass= 1 Dalton or 1.007 grams or 1.7 x 10-24

Mass= we ignore the mass of an electron

Location=moving nearly at the speed of light, electrons form a cloud around the nucleus.

Define and use atomic number and atomic mass number.

ATOMIC NUMBER: the number of protons in an element. Is written as a subscript to the left of the symbol for the element.

ATOMIC MASS NUMBER: the sum of protons plus neutrons in the nucleus of an atom. The mass number is written as a superscript to the left of an element's symbol.

Explain why isotopes have similar chemical and the

Polar covalent bond- a type of covalent bond between atoms that differ in electronegativity; the shared slightly positive.

What determines the number of covalent bonds that form?

Ionic- because of their opposite charges, cations and anions attract each other in ionic bonds. Ionic compounds are also called salts.

Some common words found in the essay are:
ENERGY LEVEL, CH4 NH, ATOMIC MASS, BONDS Define, Charge=negative Location=moving, NEUTRON Mass=, TRACE ELEMENTS, PROTON Mass=, ELECTRON Mass=, valence shell, **see fig, covalent bond, energy level shell, level shell, van der, molecular shape, energy level, covalent bonds, atoms molecules, valence electrons, , van der waals, level shell energy, 17 10-24 charge=, grams 17 10-24,
Approximate Word count = 1083
Approximate Pages = 4 (250 words per page double spaced)