2. A. International System of Units (SI)
1. Started by scientists in the 1970’s.
2. Based on the #10
3. Used by most of the world (Not the U.S.)
B. Key Terms in the SI system.
1. Mass: Measure of the amount of matter in an
object. Does not change with location.
a. SI units for mass is the gram.
3. 2. Weight: The measure of the amount of gravity
holding an object down, changes daily based on
location of the object.
a. Closer to the center of the Earth, the more the object
weighs.
b. The SI unit for weight is the NEWTON.
3. Volume: The amount of space occupied by an
object.
a. SI units is LITERS.
4. Length: A measure of distance
a. SI unit: Meters
5. SI system uses three main units: Liters, Meters,
Grams.
4. 6. Density= Mass/ Volume
a. Density is how much stuff is in how much space.
b. Density will determine if something can float on water.
c. If the density of an object (like most people) is less
than the density of water (density of water is 1)..then
they will float.
5. C. Prefixes used in the SI System.
How to Prefix Abbreviation Multiplier
Remember for prefix
King Kilo k (kg, km) 1000
Henry Hecto h (hm, hg) 100
Died Deca da (dag, dam) 10
By Base None (g, m, l) 1
Single letters!!
Drinking deci d (dm, dg) 1/10
Chocolate centi c (cm, cl, cg) 1/100
Milk milli m (ml, mm, 1/1000
mg)
6. D. Temperature (International System)
1. The U.S is the only major country to use the
Fahrenheit Scale.
2. Almost all other countries use Celsius to measure
temperature.
E. Converting Temperatures
1. Fahrenheit to Celsius
a. (F – 32) / 1.8
2. Celsius to Fahrenheit
a. (Celsius X 1.8) + 32
7. E. Freezing Point
1. Point at which a liquid becomes a solid
2. Freezing point of water :
a. 0 degrees Celsius
b. 32 degrees Fahrenheit
F. Boiling Point
1. Point at which a liquid becomes a gas.
2. Boiling point of water:
a. 100 degrees Celsius
b. 212 degrees Fahrenheit.
