Chemistry

for addition or subtraction, the limiting term in finding the number of digits is the smallest number of

• the amount of mass in a given volume
• a physical property

a quantative observation that consist of a number units and uncertainty (sig figs), depending upon the measuring device.

always has a constant composition, and can be either elements or compounds

is the amount of energy (heat) required to raise the temperature of 1 gram of water by 1 celsius degree.

the sum of protons and neutrons

have the same number of protons, but a different number of neutrons

acid reacts with base to form

• subscripts are determined first to balance ion charges
• then coefficients are added to balance atoms on each side of the equations

do not participate in the chemical reaction and are not included in the net ionic equations

produces H+ in an aqueous solution

electrons are transferred

the starting chemicals in a chemical equation are called

gives the smallest whole number ratio of atoms of each element in the compound

is used up completely when reactants are mixed to form products

the outermost electrons and determine the properties of an atom

the energy required to remove an electron from an atom

a volume of space around the nucleus where an electron is most likely to be found

moles of solute per liter of solution

the ability of an atom to attract shared electrons toward itself

results when two electron pairs are shared

the volume of 1 mole of gas at STP

• the forces between molecules
• WEAKER than the bond within the molecules

a weak acid & salt, its conjugate base

• the rate of forward reaction is equal to the rate of the reverse reaction
• as a result the reactants and the products remain the same

• thrown together elements or compounds
• they do not chemically bond
• ex: homo-chicken broth, carbonated drink motor oil hetero-dirt, italian dressing

• different elements that are chemically combined or bonded
• always has the same chemical composition
• ex: H2O OH- Vitamin D

• cannot be broken down into simpler substances by a chemical change
• ex: nitrogen gas

• something we can observe without the chemical formula changing
• ex: sugar dissolves in hot tea, salad dressing seperates, sweat evaporating

• something we can observe that changes the chemical formula
• ex: rust, burning, antacid neutralizes heartburn

Hydrogen plus N O F

metal and nonmetal bond

polar molecules H and something S- or S+

• nonpolar molecules
• diatomic molecules
• F2 Br2 H2 N2 O2

• larger ionization energy
• smaller ionization energy

• Larger atomic size
• Smaller atomic size

most active metals

most active nonmetals