1. Standards of Measurement

2. Units and Standards
Standard: an exact quantity that people agree to use to compare measurements
SI = Systeme Internationale d’Unites
All SI standards are universally accepted and understood by scientists throughout the world

3. SI Units All SI units have a base unit: SI Base Units:
Quantity Measured
Unit
Symbol
Length
Meter m
Mass
Kilogram kg
Time
Second s
Electric Current
Ampere A
Temperature
Kelvin K
Amount of substance
Mole
mol
Intensity of light
Candela cd

4. King Henry Died ….???
All other SI units are based off the base unit using prefixes
Prefix
King
Kilo
Henry
Hecto
Died
Deka By
BASE
Drinking
Deci
Chocolate
Centi
Milk
milli

5. Convert 12.54 kilometers to centimeters
The answer is centimeters

6. 457 milliliters to hectoliters
The answer is hL

7. Converting between SI units
How do you convert 1.255L to milliliters?

8. Measuring distance Length is the distance between two points
The size of the unit you measure will depend on the size of the object being measured

9. Measuring Volume Volume: amount of space occupied by an object
Measuring a cube or rectangular prism:
height x width x depth = volume ( L x w x h = V )
Example: 4 cm x 5 cm x 10 cm = 200 cm3
all measurements must be in the same unit
Units will be those used for distance but cubed
cm3 mm3 m3 etc.

10. Volume cont.
To measure the volume of a liquid you measure them in a container.

11. Measuring Mass
Mass is a measurement of the quantity of matter in an object
Is measured in grams, milligrams, kg, etc.
Density is the mass per unit volume of a material
To find density, you divide an objects mass by it’s volume
Example: 15 mg/mL, 20 g/cm3

12. Derived units
A unit obtained by combining different SI units is called a derived unit.
An SI unit multiplied by itself is also a derived unit
Examples: m3 (volume)
g/cm3 (density) or g/mL (density)

13. Measuring Time Time is the interval between two events
SI unit for time is the second

14. Temperature 3 temperature scales:
Celsius – 0oC is water freezes, 100oC is water boils
Kelvin – 0 K is absolute zero, water freezes at 273 K and boils at 373 K
No degree symbols are used
SI unit for temperature
Fahrenheit – 32oF is water freezes, 212oF water boils

15. Graphing A graph is a visual display of information or data
Line graph shows any relationship where the dependent variable changes due to a change in the independent variable (often shows changes over time)

16. Bar graphs
Bar graph is useful for comparing information collected by counting
Dependent variable goes on y axis
Independent variable goes on the x axis

17. Circle Graphs Also called a pie graph
Circle graph is used to show how some fixed quantity is broken down into parts