Scientific Notation Scientific Notation: a method for __________________________________________. Moving the decimal to the _______________exponent, to the _________________________________________. Ex g = 5.27 x g m = 5.27 x 10 7 m 3.25 x cm 3 = cm x 10 4 cm 3 = 32500cm 3 2-2

Scientific Notation Practice: 1) ml = 2) x mg = 3) kg = 4) 6.3 x 10 7 s = 2-3

Rounding Atomic Masses Rounding Atomic Masses: we will be rounding the atomic masses off the periodic table to the __________________________________________ Ex. C = g/mol = g/mol Bi = g/mol = g/mol K = g/mol = g/mol

Rounding Atomic Masses Practice: 5) N = g/mol = 6) Si = g/mol = 7) O = g/mol = 8) Ar = g/mol = 2-5

Significant Figures Non zeros are always ____________________. Zeros _____________________are significant. Leading and trailing zeros ___________________________________. Atlantic/Pacific Rule: Pacific: Point Present, start from the left, first nonzero and everything after is significant Atlantic: Point Absent, start from the right, first nonzero and everything after is significant.

Significant Figures Ex = 2 sig figs0.003 = 1 sig fig = 4 sig figs = 2 sig figs Practice: 9) = 10) = 11) x = 12) = 2-7

Significant Figures Rounding Calculations According to Sig Figs Addition and Subtraction: Round answers to the _____________________________________________: Ex = =

Significant Figures Practice: 13) )

Significant Figures Multiplication and Division: Round answers to the _______________________________________________ ________________________________________: Ex x 300 = 780 = x 2600 = = ÷ 5.63 = = ÷ 6 =13 =

Significant Figures Practice: 15) 240. ÷ 6.0 = 16) 365 ÷ 5 = 17) 32 ÷ 3 = 18) 32 x 3.0 = 2-11

Dimensional Analysis Used to convert between units. Take an equivalent (12 in. = 1 ft.) and make it into a __________________: 1 ft. or 12 in. 12 in. 1 ft. Use conversion factors to convert between units. _______________________________________________ and multiply by the conversion factor with _____________________________________________. (so they cancel) 2-12

Dimensional Analysis Ex ft. = ? in ft. x 12 in. = in. = 64.3 in. 1 ft. 32 in. = ? ft. 32 in. x 1 ft. = ft. = 2.7 ft. 12 in

Dimensional Analysis Ex in. = ? cm 3.26 in. x 1 cm= cm = 8.28 cm in. 25 g = ? kg just use your handout, move your decimal 3 places to the left 25 g = kg 5.69 oz. = ? g 5.69 oz. x 28.3 g= g = 161 g 1 oz.

Dimensional Analysis Ex. 1 year = ? S 1 year x 365 days x 24 hours x 60 min. X 60 s = 1 yr. 1 day 1 hr. 1 min. = s = s 12-15