1.4 – UNITS OF MEASUREMENT SUMMER AP CHEMISTRY HOMEWORK CHAPTER 1

SI UNITS These 5 will appear in this course!

THE METRIC SYSTEM Scientists use the metric system for all experimental measurements Based on the power of 10 (each prefix is a power of 10 away from the previous prefix) Information on how to convert between prefixes can be found in section 1.6 of this unit.

Most Important

TEMPERATURE There are two scales used in chemistry is the Kelvin and Celsius temperature scale Kelvin is the official SI system based on the concept of absolute zero. We convert between Celsius and Kelvin using: K = o C The other scale is Celsius. To convert between Celsius and Fahrenheit scale we use the equation:

DERIVED UNITS: VOLUME The SI units are used to create all other units. These units are known as derived units. Volume is a derived unit Volume is the cube of a substances length (i.e. the derived SI unit for volume is m 3 ). Any metric unit cubed can be a unit of volume (e.g. mm 3, cm 3, etc.)

DERIVED UNITS: DENSITY Density is the mass per unit of volume: Remember, less dense substances float atop more dense substances. Least dense liquid Most dense liquid

CLASS EXAMPLE Calculate the density of Hg if 1.00 x 10 2 g occupies a volume of 7.36 cm 3

CLASS EXAMPLE What is the mass in grams of a cube of gold (density = g/cm 3 ) if the length of the cube is 2.00 cm?