SI measurement system

• Fundamental units• Length meter m• Mass kilogram kg• Time seconds s• Temperature kelvin K• Amount of subs mole mol• Electric current ampere A • Luminous intensity candela cd

SI prefixes• Tera T 10^12 • Giga G 10^9• Mega M 10^6• Kilo k 10^3• Hecto h 10^2• Deca da 10^1• Deci d 10^-1• Centi c 10^-2• Milli m 10^-3• Micro u 10^-6• Nano n 10^-9• Pico p 10^-12

How units are written

• Prefix + fundamental unit

• Example:– Millimeters is written as mm. – Centimeters is written as cm.

Converting between units

• In chemistry we use a method called the factor labeling method.

• Is a problem solving method in which units are considered as variables in an algebraic equation.

Conversion factors

• Is a ratio derived from the equality between two different units and can be used to convert from one unit to the other.

• Example you have 8 quarters how many dollars do you have?

• 8 quarters X = 2 Dollars

Common conversion factors

• 1cm^3 is equal to 1 milliliter• 454 grams is equal to 1 pound• 2.54 cm is equal to 1 inch• 12 inches in a foot• 5280 feet in 1 mile

Examples

• How many meters are in 100 yards?

• A stadium is 400 meters in diameter. What is the diameter in inches?

• How many meters are in 1 km?

Examples

• A desk has a weight of 750 grams. What is the desk’s weight in pounds?

• You have 2 more miles of driving until you reach your destination. How long is it in Kilometers.

• A container has 3 sides 25ml 22ml and 20 ml. How much water in ml will the container hold?

A container has 3 sides 25in 22in and 20 in. How much water in ml will the container hold?

Temperature

• There are three ways temperature can be written.– Farenheight is the typical units that America uses.– Celsius is the units that are used overseas.– Kelvin is the standard used amongst scientist.– These are written by their first letters: – F– C– K

Temperature conversion

• F = 1.8C + 32

• C= (F -32)/1.8

• K= C + 273

Practice/Review problems

• The temperature measured 137 degrees F in the experiment. What would the degrees be in K?

Practice/Review problems

• The temperature measured 130 degrees F in the experiment. What would the degrees be in degrees C?

Review

• The temperature of the sun is 5,778 K. What is the temperature in F?

Review

• The temperature of the earth’s core is predicted to be around 10,800 F. What would be the measure of the earth’s core in degree F?

Practice/Review problems

• The temperature measured 400 degrees K in the experiment. What would the degrees be in F?

Practice/Review problems

• The temperature measured 137 degrees C in the experiment. What would the degrees be in K?

Practice/Review problems

• The temperature measured 4000 degrees K in the experiment. What would the degrees be in F?