unit 1 key concepts Flashcards
rule for recording a measured value?
you record all of the known values + one estimated value
example: known 8.1
final -> 8.10 or 8.12
how many sig figs in the following number? 50000000
1
zeros @ the end of the number depend if there is a decimal, there is not one here so no count
multiply 11.000 x 3.0
correct answer if both are measured values?
33
b/c when multiplying & dividing the answer can have no more sig figs than the measurement with the LEAST number of SIG FIGS
add 2.5810 + 1.11
correct answer if borth are measured values?
3.69
b/c the answer must have the same number of DIGITS to the RIGHT of DECIMAL point as there are in the measurement having the LEAST amount of digits to the right of decimal point
how many sig figs in the following number?
0.000010009
5
standard SI unit for volume?
Liters
which of these observations is QUALITATIVE rather than quantitative?
a) chemical reaction is complete in 2.3s
b) solid has a mass of 23.4 g
c) density of aluminum is 2.70 g/cm^2
d) salt deposits form from an evaporated liquid
d) salt deposits form from an evaporated liquid
a theory is accepted as the explanation of an observed phenomenon until
repeated observations conflict with the theory
a proposed explanation that is based on observations and can be tested is known as a
hypothesis
the relationship between the mass of a material, its volume and its density is
D = m/V
which of these abbreviations represents a volume unit?
mg
mL
mm
mmol
mL
SI base units for length and mass are
meter and kilogram
this conversion factor 1000 mL = 1 L would be used to change
liters to milliliters
the abbreviations for units of length in order from SMALL –> LARGEST
mm -> cm -> m -> km
sig fig rule:
zeros between non-zero digits are — significant
ALWAYS, they are always significant!!
ex: 1098 = 4 sig figs
