Science Chapter 12

Name the three properties of air.

1. Air has mass/weight 2. Air stores and releases heat and holds moisture 3. Air exerts pressure because it has weight

Name the three functions of the atmosphere.

1. Provide the gases necessary to support life 2. Protect living things against harmful solar radiation (ultraviolet radiation and X-ray) 3. Distribute warmth and moisture

Name the five layers of the atmosphere and name of one thing that occurs in each layer.

1. troposphere - human life, weather, clouds, planes/jets 2. stratosphere - ozone layer 3. mesosphere - meteors/ionosphere 4. thermosphere - space shuttle 5. exosphere -- satellites

What is the atmosphere made up of?

A mixture of gases, mainly Nitrogen and Oxygen, and also trace gases, such as water vapor and carbon dioxide.

What are aerosols and how are they released into the atmosphere?

Aerosols are solids such as dust, salt, pollen and tiny liquid acid droplets. Dust is released when wind picks tiny soil particles off the ground and when it is emitted by volcanoes; Salt is released when wind blows across the oceans; and Pollen is released from the plants.

By what process does water return to the atmosphere after precipitation occurs?

After precipitation causes water to flow into the lakes, oceans, rivers, and the sun energy warms up the water, EVAPORATION occurs and water goes from its liquid state to its gas state (water vapor).

Why does air have pressure?

Air has pressure because it has mass/Weight.

What is air?

Air is the mixture of gases that forms the Earth's atmosphere.

Is air pressure greater at ground level or at high elevation? Explain why.

Air pressure is greater at ground level because there are more molecules closer to Earth.

How does temperature affect the amount of water vapor air can hold?

As the water vapor moves up through the atmosphere the temperature becomes cooler and the molecules begin to slow down forming droplets of liquid water to form clouds.

Why is it possible for a high mountain in the equator to be covered by snow?

Because mountains exist in the Troposphere and in this layer of the atmosphere the temperatures are higher nearer to the surface and they become colder as the altitude increases.

What causes the atmosphere to stay around the Earth rather than float into space?

Because the atmosphere has mass it is subject to the pull of gravity and it's that pull that keeps the atmosphere around the Earth.

Which process in he water cycle occurs when water vapor (gas state) changes to liquid water?

Condensation

What is the difference between EVAPORATION and CONDENSATION?

During evaporation the temperature rises causing the water to change from a liquid state to a gaseous state. During condensation as water vapor moves up through the atmosphere the temperatures get cooler, causing the water to change from a gaseous state to a liquid state.

What are aerosols?

Dust, salt, pollen and acid droplets in the atmosphere.

Who first proved that air has weight? Describe his experiment.

Galileo Galilei - Italian astronomer and physicist (16-17th Centuries). He used two identical glass flasks that weighed the same amount, he injected one with air and then weighed them again. He noticed that the one he injected with air weighed more so he concluded that air had mass and thus, contained matter.

What is the ozone?

It is located in the Stratosphere that absorbs most of the sun's ultraviolet radiation which is harmful to living things.

What happens to gas molecules when air is heated?

Molecules start moving faster.

What creates weather changes on Earth?

Movements in the atmosphere is what causes weather changes.

What percentage of the atmosphere is made up of Nitrogen? What percentage of the atmosphere is made up of Oxygen? Which of these two gases is essential for human life?

Nitrogen - 78% and Oxygen - 21%. Oxygen is essential for human life.

What is the most abundant gas found in the Earth's atmosphere?

Nitrogen. It makes up 78% of the gases in the atmosphere.

Name the four processes that are part of the Water Cycle.

Precipitation, evaporation, transpiration and condensation.

What is one of the greatest benefits of ions in the ionosphere?

The greatest benefit of the layer of ions in the ionosphere is that it can reflect AM radio waves making long distance communications possible.

Which atmosphere layer contains electrically charged particles that reflect radio waves making long distance communication possible?

The ionosphere.

What is the water cycle?

The process that describes how water circulates between the Earth's surface and the atmosphere.

Name the three solid particles that occur in the atmosphere?

The solid particles that occur in the atmosphere are dust, pollen and salt.

What is ultraviolet radiation?

The type of energy from the sun that can damage the skin and cause cancer.

In which layers of the atmosphere does the temperature *increase as altitude increases*?

Thermosphere and stratosphere

Which layer of the atmosphere is warmest near the surface of the Earth and grows cooler with altitude?

Troposphere

In which atmosphere layers(s) does the temperature *decrease as altitude increases*?

Troposphere and mesosphere

How does the water cycle illustrate the Law of Conservation of Matter?

The Law of Conservation of Matter states that matter is neither created or destroyed but only changes its form. In the Water Cycle, water just changes its form as it goes under the different processes that make up the Water Cycle.

Which layer of the Earth's atmosphere absorbs most of the Sun's ultraviolet radiation?

The Stratosphere because it has the highest concentration of ozone.

Which atmospheric layer is farthest from the Earth's surface?

Exosphere

Which layer of the the Earth's atmosphere contains the ozone that protects living things from too much ultraviolet radiation?

Stratosphere

What factor causes the atmosphere to be divided into distinct layers?

Temperature changes in the atmosphere causes the distinct layers.

What is the atmosphere?

The atmosphere is a layer of gases surrounding the Earth that is made up of a mixture of gases, liquid water and microscopic particles of solids and other liquids