Chapter I
暂无描述。系统推荐的高质量记忆内容，适合每天坚持背诵学习。
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how many SF do exact #’s have
infinite
for multiplication/division, answer has _____ for sig figs/LSP
has same # of SF as least precise factor
for addition/subtraction, answer has _____ for sig figs/LSP
has same LSP as factor w/ furthest-left one; nothing to do w/ sig figs
when calculating something that uses a mix of the 4 operations, how do you show your work (3 things)
• do add/sub 1st, mult/div 2nd • do not round the # until the final answer, but still keep track of the # of sig figs & LSP • show answer that calc gave as well as the final rounded answer
1 Terameter equation
1 Tm = 1 x 10¹² m
1 Gigameter equation
1 Gm = 1 x 10⁹ m
1 Megameter equation
1 Mm = 1 x 10⁶ m
1 Decimeter equation
1 dm = 1 x 10⁻¹ m
1 Micrometer equation
1 µm = 1 x 10⁻⁶ m
1 Nanometer equation
1 nm = 1 x 10⁻⁹ m
1 Picometer equation
1 pm = 1 x 10⁻¹² m
1 Femtometer equation
1 fm = 1 x 10⁻¹⁵
conversions aren’t exact #’s, T or F
F
3 things about density
• D = m/v • take m & v from the same sample • use pipet/grad cylinder for liquid v
3 steps to show calculations w/ conversions
1) show the original equation you use 2) show the equation w/ #’s subbed in 3) show ans w/ proper sig figs & units
def accuracy
close to correct value
def precision
close to other results
conversion from K to °C
Tₖ = T°꜀ + 273.15
conversion from °F to °C
T°բ = 1.8(T°꜀) + 32
3 ways to separate mixtures
• Decant (pour liquid off sediment) • Filtration • Distillation (boiling)
def intensive - 3 things
• physical prop • doesn’t dep on amt of subst there • used to ID subst
def extensive - 3 things
• physical prop • does dep. on amt of subst there • like mass, vol, heat content
what does a chem form show
compound, like H2O
what does a chem equation show
a reaction