1. Section 10.1 Learning Goals
Define density in terms of mass and volume.
Identify units used to express the density of materials.
Apply the density formula to solve problems.

2. 10.1 Density
Density describes how much mass is in a given volume of a material.

3. 10.1 Determining Density
To find the density of a material, you need to know the mass and volume of a solid sample of the material.
Mass is measured with a balance or scale.
Use the displacement method or calculate the volume.

4. D V m D

5. A solid wax candle has a volume of 1,700 mL.
Solving Problems
A solid wax candle has a volume of 1,700 mL.
The candle has a mass of 1.5 kg (1,500 g).
What is the density in g/mL of the candle? *use sig digs*

6. Calculating Density Looking for: Given: Relationship: Solution:
Solving Problems
Calculating Density
Looking for:
…the density of the candle
Given:
…mass = 1500 g; volume = 1700 mL
Relationship:
D = m/V
Solution:
1,500 g ÷ 1,700 mL = g/mL
# Sig. fig = .88 g/mL

7. 10.1 Density
Solids, liquids and gases are matter, so they all have density.
The density of water is about one gram per cubic centimeter.

8. 10.1 Density
The units used for density depend on whether the substance is solid or liquid.
For liquids use units of grams per milliliter (g/mL)
For solids use density in units of g/cm3 or kg/m3.

10. 10.1 Density of common materials
Regardless of how much or what shape it is in, objects made of the same substance have the same density.

11. 10.1 Density of common materials
Liquids tend to be less dense than solids of the same material.
Ex. Solder
What is the density of the solid solder? *use sig digs*
What is the density of the liquid solder? *use sig digs* . .

12. 10.1 Density of common materials
Water is an exception to this rule.
The density of solid water (ice) is less than the density of liquid water.

13. 10.1 Density Density changes between different substances because:
Atoms have different masses.
Atoms may be “packed” tightly or loosely.

14. 10.2 Properties of Solids
Different kinds of matter have different characteristics.
Characteristics that can you observe directly are called physical properties.
Physical properties include color, texture, density, brittleness, and state (solid, liquid, or gas).
Ex. Iron is solid at room temp.

15. 10.2 Properties of Solids
A physical change is any change in the size, shape, or phase of matter in which the identity of a substance does not change.
For example, when water is frozen, it changes from a liquid to a solid.

16. 10.2 Properties of Solids
Properties that can only be observed when one substance changes into a different substance are called chemical properties.
Any change that transforms one substance into a different substance is called a chemical change.
Iron reacts with oxygen to form iron oxide.
Ex. If you leave a nail outside, it rusts.