chemistry: unit 2 - scientific measurement

quantity

a property that we measure

ex: mass, volume, temperature, time, distance

unit

a set increment that we use to report a measurement

ex: height→inches

systems of measurement

the metric system is what’s used in chemistry

mass

how heavy something is

ex: grams, kilograms, milligrams

volume

how much space something takes up

ex: liquid → liters, milliliters

solid → meters cubed

scientific notation

a system for writing numbers in science

kilo

makes things 1000 times bigger

milli

makes things 1000 times smaller

centi

makes things 100 smaller

tenth place

0.1

hundredth place

0.01

thousandth place

0.001

cm * cm

cm²

m * m * m

m³

if we divide measurements our solution will have units that are

written as a fraction

rule for adding and subtracting measurements

round so that the answer has the same number of places after the decimal as the given info with the smallest number of places after the decimal

rule for multiplying and dividing measurements

round so that the answer has the same number of significant figures as the given info with the smallest number of significant figures