1. Tools, Measurement and Safety
L. LaRosa for T. Trimpe
Modified by Linda Williams 2010

2. The International System of Units
In the late 1700s, the French Academy of Sciences set out to make a simple and reliable measurement system. This system is now the International System of Units (SI).
Because all SI units are expressed in multiples of 10, changing from one unit to another is easy.

3. Length Length or distance is measured in meters (m).
A meter is the basic SI unit of length. Other SI units of length are larger or smaller than the meter by multiples of 10.
Ex- 1 m = 10 decimeter
1 m = 100 centimeters
1 m = 1000 mm

4. MASS 1000 g = 1 kg 1 mg = .000001 kg 1 metric ton = 1000 kg
Mass can be defined as the amount of matter in an object. The kilogram is the basic SI unit for mass.
The kilogram is used to describe the mass of large objects.
1000 g = 1 kg
1 mg = kg
1 metric ton = kg

5. VOLUME
Volume is the amount of space that something occupies.
Liquid volume is expressed in liters (L).
Volumes of solids are expressed as cubic centimeters (cm3)
1 L = 1000 ml
1 ml = 1 cm3

6. What is Density?
DENSITY is a physical property of matter, as each element and compound has a unique density associated with it.
For example the known density of water is 1 g /ml.
You can think of density in a qualitative manner as the measure of the relative "heaviness" of objects with a constant volume.

7. Units for density may be seen as g/ml or g/cm3
Density Formula
Density is defined as the amount of matter in a given volume.
Density = mass
volume
Units for density may be seen as g/ml or g/cm3

8. Density in Comparison to Water
In chemistry, the density of many substances is compared to the density of water. Does an object float on water or sink in the water? If an object such as a piece of wood floats on water it is less dense than water vs. if a rock sinks, it is more dense than water.

9. www.middleschoolscience.com 2008
Will it float in water? Determine if the following shapes will float in water by calculating the density for each item. D = M / V
Mass: 15 g
Volume: 20 mL
Mass: 1000 g
Volume: 50 mL
Mass: 225 g
Volume: 100 mL
Mass: 10 g
Volume: 200 mL
2008

10. www.middleschoolscience.com 2008
Will it float in water? Determine if the following shapes will float in water by calculating the density for each item. D = M / V
Float
Float
Mass: 15 g
Volume: 20 mL
Density:
0.75 g/mL
Mass: 1000 g
Volume: 50 mL
Density:
20.0 g/mL
Mass: 225 g
Volume: 100 mL
Density:
2.25 g/mL
Mass: 10 g
Volume: 200 mL
Density:
0.05 g/mL
If the density is less than 1.0 g/cm3 then it will float. 1 g/mL = 1 g/cm3
2008

11. Temperature
The temperature of a substance is the measurement of how hot or cold a substance is.
Temperature can be measured in degrees Fahrenheit, degrees Celsius, or degrees Kelvin.