# properties of matter

## chemical properties of matter

Some properties of matter can be measured or observed only when matter undergoes a change to become an entirely different substance. These properties are called chemical properties. They include flammability and reactivity.

## flammability

Flammability is the ability of matter to burn. Wood is flammable; iron is not. When wood burns, it changes to ashes, carbon dioxide, water vapor, and other gases. After burning, it is no longer wood.

## mass

Mass is the amount of matter in a substance or object. Mass is commonly measured with a balance. A simple mechanical balance is shown in Figure 3.1. It allows an object to be matched with other objects of known mass. SI units for mass are the kilogram, but for smaller masses grams are often used instead.

## mass versus weight

The more matter an object contains, generally the more it weighs. However, weight is not the same thing as mass. Weight is a measure of the force of gravity pulling on an object. It is measured with a scale, like the kitchen- scale in Figure 3.2. The scale detects how forcefully objects in the pan are being pulled downward by the force of gravity. The SI unit for weight is the newton (N). The common English unit is the pound (lb). With Earths gravity, a mass of 1 kg has a weight of 9.8 N (2.2 lb). Problem Solving Problem: At Earths gravity, what is the weight in newtons of an object with a mass of 10 kg? Solution: At Earths gravity, 1 kg has a weight of 9.8 N. Therefore, 10 kg has a weight of (10 9.8 N) = 98 N. You Try It! Problem: If you have a mass of 50 kg on Earth, what is your weight in newtons? An object with more mass is pulled by gravity with greater force, so mass and weight are closely related. However, the weight of an object can change if the force of gravity changes, even while the mass of the object remains constant. Look at the photo of astronaut Edwin E. Aldrin Jr taken by fellow astronaut Neil Armstrong, the first human to walk on the moon, in Figure 3.3. An astronaut weighed less on the moon than he did on Earth because the moons gravity is weaker than Earths. The astronauts mass, on the other hand, did not change. He still contained the same amount of matter on the moon as he did on Earth. The amount of space matter takes up is its volume. How the volume of matter is measured depends on its state. The volume of liquids is measured with measuring containers. In the kitchen, liquid volume is usually measured with measuring cups or spoons. In the lab, liquid volume is measured with containers such as graduated cylinders. Units in the metric system for liquid volume include liters (L) and milliliters (mL). The volume of gases depends on the volume of their container. Thats because gases expand to fill whatever space is available to them. For example, as you drink water from a bottle, air rushes in to take the place of the water. An "empty" liter bottle actually holds a liter of air. How could you find the volume of air in an "empty" room? The volume of regularly shaped solids can be calculated from their dimensions. For example, the volume of a rectangular solid is the product of its length, width, and height (l w h). For solids that have irregular shapes, the displacement method is used to measure volume. You can see how it works in Figure 3.4 and in the video below. The SI unit for solid volumes is cubic meters (m3 ). However, cubic centimeters (cm3 ) are often used for smaller volume measurements.

## what is matter

Both you and the speck of dust consist of atoms of matter. So does the ground beneath your feet. In fact, everything you can see and touch is made of matter. The only things that arent matter are forms of energy, such as light and sound. Although forms of energy are not matter, the air and other substances they travel through are. So what is matter? Matter is defined as anything that has mass and volume.

## density

Density is an important physical property of matter. It reflects how closely packed the particles of matter are. Density is calculated from the amount of mass in a given volume of matter, using the formula: Density (D) = Mass (M) Volume (V ) Problem Solving Problem: What is the density of a substance that has a mass of 20 g and a volume of 10 mL? Solution: D = 20 g/10 mL = 2.0 g/mL You Try It! Problem: An object has a mass of 180 kg and a volume of 90 m3 . What is its density? To better understand density, think about a bowling ball and a volleyball. The bowling ball feels heavy. It is solid all the way through. It contains a lot of tightly packed particles of matter. In contrast, the volleyball feels light. It is full of air. It contains fewer, more widely spaced particles of matter. Both balls have about the same volume, but the bowling ball has a much greater mass. Its matter is denser.

## kqed aerogel

It looks like frozen smoke, and its the lightest solid material on the planet. Aerogel insulates space suits, makes tennis rackets stronger and could be used one day to clean up oil spills. Lawrence Livermore National Laboratory scientist Alex Gash shows us some remarkable properties of this truly unique substance. For more information on aerogel, see http://science.kqed.org/quest/video/quest-lab-aerogel/ . MEDIA Click image to the left or use the URL below. URL:

## physical properties of matter

Matter has many properties. Some are physical properties. Physical properties of matter are properties that can be measured or observed without matter changing to a different substance. For example, whether a given substance normally exists as a solid, liquid, or gas is a physical property. Consider water. It is a liquid at room temperature, but if it freezes and changes to ice, it is still water. Generally, physical properties are things you can see, hear, smell, or feel with your senses.

## examples of physical properties

Physical properties include the state of matter and its color and odor. For example, oxygen is a colorless, odorless gas. Chlorine is a greenish gas with a strong, sharp odor. Other physical properties include hardness, freezing and boiling points, the ability to dissolve in other substances, and the ability to conduct heat or electricity. These properties are demonstrated in Figure 3.5. Can you think of other physical properties?

## reactivity

Reactivity is the ability of matter to combine chemically with other substances. For example, iron is highly reactive with oxygen. When it combines with oxygen, it forms the reddish powder called rust (see Figure 3.6). Rust is not iron but an entirely different substance that consists of both iron and oxygen.

## instructional diagrams

No diagram descriptions associated with this lesson

## questions

All of the following are matter except

``````a. air.

b. gas.

-->  c. sound.

d. water.
``````

The volume of a liquid may be measured with a(n)

``````a. scale.

b. balance.

c. metric ruler.

``````

A physical property of matter is

``````-->  a. color.

b. flammability.

c. reactivity.

d. none of the above.
``````

Chemical properties of matter include

``````-->  a. ability to rust.

b. odor.

c. hardness.

d. all of the above.
``````

If an object has a mass of 42 kg and a volume of 2 m3 what is its density?

``````a. 84 kg/m3

b. 44 kg/m3

-->  c. 21 kg/m3

d. 0.05 kg/m3
``````

Sound is a form of matter.

``````a. true

-->  b. false
``````

Air is not matter.

``````a. true

-->  b. false
``````

The SI unit for weight is the kilogram.

``````a. true

-->  b. false
``````

The volume of a gas depends on the volume of its container.

``````-->  a. true

b. false
``````

The SI unit for liquid volume is the kilogram.

``````a. true

-->  b. false
``````

Physical properties of matter are typically things you can detect with your senses.

``````-->  a. true

b. false
``````

The volume of a liquid depends on the volume of its container.

``````a. true

-->  b. false
``````

Density refers to how closely packed the particles of matter are.

``````-->  a. true

b. false
``````

Physical properties include the ability to conduct heat.

``````-->  a. true

b. false
``````

Chemical properties include freezing and boiling points.

``````a. true

-->  b. false
``````

Hardness is a physical property of matter.

``````-->  a. true

b. false
``````

Density is a physical property of matter.

``````-->  a. true

b. false
``````

Weight is measured with a scale.

``````-->  a. true

b. false
``````

The density of matter depends on its mass and volume.

``````-->  a. true

b. false
``````

After a log burns, it is still wood.

``````a. true

-->  b. false
``````

ability of matter to burn

``````a. chemical property

-->  b. flammability

c. mass

d. matter

e. physical property

f. reactivity

g. volume
``````

amount of space taken up by matter

``````a. chemical property

b. flammability

c. mass

d. matter

e. physical property

f. reactivity

-->  g. volume
``````

anything that has mass and volume

``````a. chemical property

b. flammability

c. mass

-->  d. matter

e. physical property

f. reactivity

g. volume
``````

type of property that can be measured or observed only when matter changes to an entirely different

``````-->  a. chemical property

b. flammability

c. mass

d. matter

e. physical property

f. reactivity

g. volume
``````

type of property that can be measured or observed without matter changing to a different substance

``````a. chemical property

b. flammability

c. mass

d. matter

-->  e. physical property

f. reactivity

g. volume
``````

ability of a substance to combine chemically with other substances

``````a. chemical property

b. flammability

c. mass

d. matter

e. physical property

-->  f. reactivity

g. volume
``````

amount of matter in a substance or object

``````a. chemical property

b. flammability

-->  c. mass

d. matter

e. physical property

f. reactivity

g. volume
``````

Which of the following is not made of matter?

``````-->  a. light

b. solid

c. liquid

d. gas
``````

Mass is measured with a

``````a. scale.

-->  b. balance.

d. metric ruler.
``````

Examples of physical properties of matter include

``````a. color.

b. odor.

c. hardness.

-->  d. all of the above.
``````

Which of the following is a chemical property of matter?

``````a. ability to conduct heat

b. ability to conduct electricity

-->  c. flammability

d. all of the above
``````

What is the density of an object that has a mass of 30 kg and a volume of 0.5 m3 ?

``````-->  a. 60 kg/m3

b. 0.02 m3 /kg

c. 15 m3  kg

d. none of the above
``````

The ability of iron to rust is as example of

``````-->  a. reactivity.

b. flammability.

c. displacement.

d. a physical property.
``````

What is the SI unit for mass?

``````a. m3

b. mL

c. cm3

-->  d. kg
``````

## diagram questions

No diagram questions associated with this lesson