matter

anything that occupies space and has mass

pure substance that cannot be broken down into other substances by chemical or physical means

element critical to health that makes up less than .01% of body mass

nucleus

# of protons in an atoms nucleus,different for each element

chemical bond that forms when two atoms share electrons

reactant

polar molecule

opposite ends have opposite electric charges

tendancy of molecules of the same kind to stick to one another

attraction between unlike molecules

bond created by the weak attraction of a slightly positive hydrogen atom to a slightly negative portion of another molecule

total amount of energy associated with the random movement of atoms and molecules in a sample of matter

measure of the average energy of random motion of particles and a substance

uniform mixture of two or more substnces

substance in a solution that dissolves the other substances and is present in the greater amount

substance in  a solution that is dissolved and is present in a lasser amount

solution in which water is the solvent

coumpound that donates H+ ions to an aqueous solution and measures less than 7 on the pH scale

coumpound that removes H+ ions from an aqueous solution and that measures more than 7 on the pH scale

range of #s used to describe how acidic or basic a solution is;

ranges from 0 (most acidic) to 14 (most basic)

buffer

substance that maintains a fairly constant pH in a solution by accepting H+ ions when their levels rise and donating H+ ions when their levels fall