Essential Question:

What are the characteristics of the Earth’s atmosphere?

Science 7

Homework: ScienceRead “The Carbon Cycle” on the wiki

Complete homework questions for Tuesday

Next Science Test:

Today’s Topic:

What is the atmosphere?

Video:

Introduction to the Atmosphere

Introduction to the Atmosphere: Vocabulary

This is the TOTAL collection of ALL the gases that surrounds Earth and helps to maintain and support life. Without this, life could not exist on the planet Earth.

ATMOSPHERE

Introduction to the Atmosphere: Vocabulary

There are three major functions of the atmosphere:To block out harmful radiation from reaching Earth’s surface

To keep the planet warmTo provide materials necessary for life to exist on Earth (example: oxygen)

Introduction to the Atmosphere: Vocabulary

There are several properties to remember thatFLUID- Because it is a gas, the air in the atmosphere is constantly flowing from one

place to anotherDENSITY- the air in different parts of the atmosphere has different densities (the

gas in some parts is more spread out than in other parts)Within a fluid, such as the atmosphere, less dense gases will rise to the top and

more dense gases will sink to the bottom

Introduction to the Atmosphere: Vocabulary

This is the distance or height above sea level of a given location.ALTITUDE (ELEVATION)

As the altitude (elevation) of a location in the atmosphere increases, the density of the air in that location DECREASES (gets less dense).

Introduction to the Atmosphere: Vocabulary

Air Density, Altitude (elevation), and Temperature within the atmosphere have a great effect on one another:

As air (and other fluids) HEAT UP, the air EXPANDS (becomes less dense)As air (and other fluids) COOL DOWN, the air CONTRACTS (becomes more

dense)As air spreads out, it CONDUCTS heat less efficiently, causing the temperature

to dropTherefore, as ALTITUDE INCREASES, AIR DENSITY DECREASES, which causes

TEMPERATURE TO DECREASE

Composition of the Atmosphere: VocabularyThere are many different gases that make up Earth’s atmopshere. Here are four of them:NITROGEN- the most common gas in the atmosphere; the majority of the atmosphere is made up of this gasOXYGEN- the second most common gas in the atmosphere; it makes up over 20% of Earth’s atmosphere;

used by living things as part of respirationCARBON DIOXIDE- this gas makes up less than 1% of the Earth’s atmosphere; it plays an important role in

heating the planetWATER VAPOR- this gas makes up less that 1% of the Earth’s atmosphere, though the total amount varies

because of the cycling of this substance through its solid and liquid forms; it is necessary for life on Earth

Second Video:

Composition of the Atmosphere

Your Task:Your groups will use the information from your homework, your notes and the videos to complete the diagrams on the “Composition of the Atmosphere” worksheet

Your groups may work together

Exit Ticket: Access the “Exit Tickets” page of DeBolt’s wiki

Click on the link for today’s exit ticketComplete the quiz before leaving className format:“your period number, Last name, First name”