Card Set Information
Chemistry and Measurement
A tentative explanation based on observations
An observation of natural phenomena carried out in a controlled manner so that the results can be duplicated
States a measurable relationship
Tested explanation of basic natural phenomena
the quantity of matter in a material
Law of Conservation of Mass
Matter can neither be created nor destroyed during a normal chemical reaction.
What is the difference between mass and weight?
Weight depends on gravity
Have a fixed shape and fixed volume
Have a fixed volue but not a fixed shape
Do not have a fixed volume or shape
A change in which the chemical composition of the sample does not change
A change in which the chemical composition of the sample changes. (new matter)
characteristics of a material that can be observed without changing the substance (its chemical identity)
characteristic of a material which is evident when the material undergoes a chemical change.
a pure substance that cannot be broken down any further by chemical means.
oxygen, mercury, sulfur
A combination of more than one element that can be broken down further by chemical reations.
a mixture in which the properties vary within a sample
a mixture in which the properties are constant throughout the sample.
How close the measurements are to one another
Closeness of a measurement ot its true value
measurements cannot be exact
digits in a mesurement that include all certain digits plus a finial digit with some uncertainty.
Rules to significant digits
confined zeros significant
leading zeros not significant
trailing zeros significant with decimal
if next digit is >5 round up
if next digit is <5 round down
if next digit is =5 round to nearest even number
Adding and Subtracting Sig Figs
Last common place that each number has
Round answer to place of least sig fig
Multiplying and Dividing with Sig Figs
Look at the number of sig fig in all values; report the fewest number of sig fig in answer
exponential notation where there is exactly one non-zero digit the the left of the decimal
positive <- decimal -> negative
Base units of metric system
length -> meter -> m
mass -> gram -> g
volume -> liter -> L
time -> second -> s
Measurement staircase and rules
tera, giga, mega, kilo base
deci, centi, milli, micro, nano, pico
up stair divide by 10, down stair multiply by 10
= (9/5) T
+ 32.000 F
Length * Width * Height
Mass / Volume
g / mL
Common conversions with liters
1 L = 1 m
1 mL = 1 cm