The gases of Earth’s Atmosphere

Objectives: TLW identify the gases that make up most of the atmosphere and their percentages. TLW describe the role of atmospheric gases in supporting life on Earth. TLW contrast the present composition of the atmosphere to the composition before human life. This lesson plan will teach students the composition of the atmosphere as a mixture of mostly nitrogen, oxygen, argon, and carbon dioxide. Water vapor, ozone, and other trace gases make up the remainder. Each gas plays a vital role in maintaining life on Earth. The relative abundance of these gases in the atmosphere has changed due to the air pollution, such as the burning of fossil fuels and the use of products containing chlorofluorocarbons. Relevant Standards/ Benchmarks: GLCES:

E.FE.M.1 Atmosphere- The atmosphere is a mixture of nitrogen, oxygen, and trace gases that include water vapor. The atmosphere has different physical and chemical composition at different elevations.

E.FE.07.11 Describe the atmosphere as a mixture of gases.

S.IP.00.15 Make accurate measurements with appropriate (non-standard) units for the measurement tool.

S.IA.00.12 Share ideas about science through purposeful conversation.

UNIFYING CONCEPTS NSES:

Change, constancy, measurement. Gases of the atmosphere will be represented as different colored macaroni noodles, and the atmosphere will be represented in a glass jar that is at least 1L in volume. In groups, the students will measure how much of a particular macaroni noodle is needed to represent its corresponding gas’s percentage in the atmosphere. The students will also analyze two graphs depicting the concentration of ozone and carbon dioxide over time, as these concentrations have been altered due to air pollution.

Materials and Methods:

- candle with a lid

- match or lighter

- macaroni noodles of four different colors

- large glass jar (at least 1L)

- graduated cylinders

- Instructional methods: lecture, discussion, demonstration, and cooperative learning

Safety:

- Do not let the student light or hold the candle during the engage portion. If the macaroni noodles were made using rubbing alcohol, inform students not to eat the macaroni noodle. Rubbing alcohol is highly flammable; so keep the noodles away from any flame/ heat source.

Engage:! ! !~10 minutes!

!Anticipatory Set: Light the candle for all students to see. Ask students the following questions:

1. What is needed to keep a flame burning? 2. What do you think will happen when I put a lid on the candle?

After the students commit to a prediction by writing it down, allow students to share their predictions aloud. Then put a lid on top of the candle so the flame goes out. Ask the students think, pair, and share the following question:

3. Why did the flame go out? Allow students to share their explanations of the demonstration, opening into a class discussion. Access prior knowledge by asking if they have they ever heard that you should close the windows if there is a fire? Explain to students that the atmosphere is a thin layer of gases that surrounds the Earth. Oxygen in the air is needed for fire to keep burning, which is a combustion reaction, and when you put the lid on, the oxygen ran out to make carbon dioxide and water.

Share the objectives of this lesson with the students by saying the following: “Today we will find out what gases make up the atmosphere. In addition to oxygen, there are other gases in the atmosphere, and we will take a look at their percent. We will also see how the amounts of two gases have changed over time due to pollution.” !

Explore: ~15 minutes

Students will make a model of the percentages of gases in the atmosphere using macaroni noodles. Each color of macaroni noodle represents a specific gas in the atmosphere: Nitrogen = 78% (blue) Oxygen = 21% (red) Argon = 0.9% (yellow) Carbon Dioxide = 0.03% (green) Atmosphere = 1L (glass jar) Split the class into 5 heterogeneous groups. Each group will be assigned one color/gas or the atmosphere jar. Do not tell the students their gas! Just tell them that the entire volume of the ‘atmosphere’ is 1L. Give each student one of the following notecards (found in Appendix A) that corresponds with his group’s assignment. Allow students to use calculators and graduated cylinders. When the students have measured their noodles, they can pour them into the ‘atmosphere’ jar. Once all groups have poured their noodles into the jar, shake the jar and hold up the atmosphere for all to see. Provide students with a pie chart showing the gases of the atmosphere on the overhead or as handouts. Have students assign the gas to the noodle in the jar in their groups using the pie charts. Have students share their answers with the class.

Explain: ~20 minutes Students will take notes on the gases of the atmosphere with the skeleton notes in Appendix A. Full notes will be provided with the PowerPoint also in Appendix A. The PowerPoint notes includes the following information:

Nitrogen makes up 78% of the atmosphere. All plants and animals need nitrogen to make proteins and DNA, but the nitrogen in the atmosphere is not in a form that they can use. Bacteria can ‘fix’ nitrogen into a form that plants can use. Oxygen makes up 21% of the atmosphere. Oxygen is needed for respiration, or to burn food for energy. Argon makes up 0.9% of the atmosphere. Carbon dioxide only makes up 0.03%. Carbon dioxide is needed for photosynthesis and for trapping heat in the atmosphere, which allows water to exist as a liquid. Checking for understanding: Ask students the following question:

1. What two gases make up about 99% of the atmosphere?

It is suggested to use the site polleverywhere.com to have students engaged in the questions. Students can text in their answers to the website, and students can see all responses to the poll in live time.

Other gases in the atmosphere include methane, water vapor, and ozone. Ozone is a form of oxygen with three oxygen atoms in each molecule. Ozone in the ozone layer is needed to block harmful ultraviolet radiation. The amount of water vapor in the atmosphere constantly changes. The weather changes as a result of the change in water vapor. Carbon dioxide, methane, and water vapor are greenhouse gases. Greenhouse gases are responsible for trapping heat. These gases are needed to keep our planet warm enough so that water can exist as a liquid. Checking for understanding: Ask students the following questions:

2. Why do we need the ozone layer? 3. Why do we need carbon dioxide?

Have students share their answers with the class.

Elaborate: ~15 Minutes Guided Practice: Give students two graphs, one showing the increase in carbon dioxide over time and the other graph showing changes in the concentration of ozone over time. Tell the students that humans have changed the amount of gases that are present in the air, but don’t say which gas or by how much. Ask the students the following question:

“Using the two graphs, describe how the atmosphere has changed over time.” Walk around as students are talking. Have the students talk with their partner for a couple minutes. They will then play rock, paper, scissors. The winner of the game will stand up and share their answers. As students describe how carbon dioxide concentrations have increased and the concentration of ozone has primarily decreased, describe how these changes occurred. In 1970, scientists noticed that the ozone layer above Antarctica was thinning. A group of chemicals called chlorofluorocarbons (CFCs) were used in aerosol spays, air conditions, and cleaning machinery. Scientists discovered that these CFCs were depleting the ozone layer. People burn fossil fuels for energy, such as electricity. When fossil fuels are burned, they release carbon dioxide into the atmosphere. The carbon dioxide has accumulated in the atmosphere over the years.

Evaluate: ~10 Minutes Have students individually complete the exit slip in Appendix A. The answer key can also be found in Appendix A. Bloom’s Taxonomy Knowledge: Know the gases of the atmosphere and their abundance. Comprehension: Understand how each gas is important for human life. Analysis: Analyze how the composition of the air has changed due to humans. Learning styles and Accommodations Tactile: Students will be measuring macaroni noodles with graduated cylinders. Visual: Students can look at the macaroni noodle model of the atmosphere to visualize the composition of the atmosphere. There are numerous graphs depicting the gases of the atmosphere. Auditory: Give directions and notes verbally. ELL will be grouped with students who speak English as a first language.

Appendix A Table&of&Contents:&

!Page&7&& & Engage:&Model&of&the&Gases&of&the&Atmosphere&Group&Notecards&&Pages&8>9& & Explain:&Student&Skeleton&Notes&&Pages&10>11& & Explain:&Full&Notes&&Page&12& & Elaborate:&Student&Graph&Handout&&Page&13& & Evaluate:&Student&Exit&Slip&&Page&14& & Evaluate:&Exit&Slip&Key&

The&blue&macaroni&noodle&represents&a&gas&in&the&atmosphere.&&This&gas&makes&up&78%&of&the&atmosphere.&&&&Pretend&the&atmosphere&is&a&1.0&L&bag.&&What&volume&of&the&red&macaroni&noodle&do&you&need?&&&&Measure&the&volume&of&blue&macaroni&noodle&needed.&&Pour&it&into&the&zipblock&bag.&&You&may&use&calculators&and&a&graduated&cylinder.&&&

The&red&macaroni&noodle&represents&a&gas&in&the&atmosphere.&&This&gas&makes&up&21%&of&the&atmosphere.&&&&Pretend&the&atmosphere&is&a&1.0&L&bag.&&What&volume&of&the&red&macaroni&noodle&do&you&need?&&&&Measure&the&volume&of&red&macaroni&noodle&needed.&&Pour&it&into&the&2L&bottle.&&You&may&use&calculators&and&a&graduated&cylinder.&&&

The&green&macaroni&noodle&represents&a&gas&in&the&atmosphere.&&This&gas&makes&up&0.03%&of&the&atmosphere.&&&&Pretend&the&atmosphere&is&a&1.0&L&bag.&&What&volume&of&the&red&macaroni&noodle&do&you&need?&&&&Measure&the&volume&of&green&macaroni&noodle&needed.&&Pour&it&into&the&zipblock&bag.&&You&may&use&calculators&and&a&graduated&cylinder.&&&

The&yellow&macaroni&noodle&represents&a&gas&in&the&atmosphere.&&This&gas&makes&up&0.09%&of&the&atmosphere.&&&&Pretend&the&atmosphere&is&a&1.0&L&bag.&&What&volume&of&the&red&macaroni&noodle&do&you&need?&&&&Measure&the&volume&of&yellow&macaroni&noodle&needed.&&Pour&it&into&the&2L&bottle.&&You&may&use&calculators&and&a&graduated&cylinder.&&&

Pretend&that&the&atmosphere&is&only&1L&in&volume.&&Measure&how&much&1L&is&on&a&glass&jar.&Mark&off&where&the&1L&is&on&the&glass&jar.&You&may&use&graduated&cylinders,&markers,&tape,&and&water.&&&&

Name!_______________________! Date______________!!

Atmospheric,Gases,,Notes:

The ________________ is a thin layer of air that surrounds Earth. Without

the atmosphere, life on Earth would not exist!

The gases of the atmosphere: Nitrogen __________% Needed for: Oxygen __________% Needed for: Argon __________% Carbon Dioxide __________% Needed for:

Other gases in the atmosphere include _______________,

________________, and __________________. Ozone is a form of

oxygen with _____ oxygen atoms in each molecule. Ozone in the ozone

layer is needed to block harmful ________________

________________.

The amount of __________________ in the atmosphere changes. The

__________________ changes as a result of the change in water vapor.

Carbon dioxide, methane, and water vapor are

_________________________ gases. __________________ gases are

responsible for trapping __________________. These gases are needed

to keep our planet warm enough so that water can exist as a

________________.

Name!_______________________! Date______________!

!Atmospheric,Gases,

,Notes:

The atmosphere is a thin layer of air that surrounds Earth. Without the

atmosphere, life on Earth would not exist!

The gases of the atmosphere: Nitrogen 78% Needed for: to make proteins and DNA Oxygen 21% Needed for: respiration/ burning food energy Argon 0.9% Carbon Dioxide 0.03% Needed for: photosynthesis and trapping heat to allow water to exist as a liquid

Other gases in the atmosphere include methane, water vapor, and

ozone. Ozone is a form of oxygen with 3 oxygen atoms in each molecule.

Ozone in the ozone layer is needed to block harmful ultraviolet radiation.

The amount of water vapor in the atmosphere changes. The weather

changes as a result of the change in water vapor.

Carbon dioxide, methane, and water vapor are greenhouse gases.

Greenhouse gases are responsible for trapping heat. These gases are

needed to keep our planet warm enough so that water can exist as a

liquid.

Name___________________ Date__________ Hr_____

In your group and using the two graphs, describe how the atmosphere has changed over time. Write your response on the back of this handout. When your group is done, play rock, paper, scissors. The group winner will stand and the group response with the class.

The Gases of the Atmosphere: Exit Slip

1. Complete the following table.

The Gases of the Atmosphere

Gas Percentage

78%

Oxygen %

0.9%

Carbon dioxide %

2. Match the gases to their role in supporting life on Earth.

________Nitrogen

________Oxygen

________Ozone

________Carbon Dioxide

3. Describe how air pollution has changed the concentrations of carbon dioxide

and ozone over time.

a. Blocks harmful ultraviolet radiation

b. Respiration; burning food energy

c. Traps heat to allow water to exist as a liquid

d. Needed to make proteins and DNA

The Gases of the Atmosphere: Exit Slip Key

1. Complete the following table.

The Gases of the Atmosphere

Gas Percentage

nitrogen 78%

Oxygen 21 %

argon 0.9%

Carbon dioxide 0.03 %

2. Match the gases to their role in supporting life on Earth.

d. Nitrogen

b. Oxygen

a. Ozone

c. Carbon Dioxide

3. Describe how air pollution has changed the concentrations of carbon dioxide

and ozone over time.

a. Blocks harmful ultraviolet radiation

b. Respiration; burning food energy

c. Traps heat to allow water to exist as a liquid

d. Needed to make proteins and DNA

An#cipatory,Set,

Look,at,the,candle,burning,on,the,front,table.,,Do,not,touch,it.,,1.   What,is,needed,to,keep,a,flame,burning?,2.   What,do,you,think,will,happen,when,I,put,a,

lid,on,the,candle?,,Explain,your,answer.,

An#cipatory,Set,

3.#Why#did#the#flame#go#out?#

The#Gases#of#the#Atmosphere#

The#Gases#of#the#Atmosphere#The#atmosphere,is#a#thin#layer#of#gases#surrounding#Earth.##It#is#made#up#of#the#following#gases:##•  Nitrogen##

•  78%#•  Needed#to#make#proteins#and#DNA#

•  Oxygen#•  21%#•  RespiraJon;#burning#food#energy##

•  Carbon#dioxide#•  0.03%#•  Photosynthesis#and#trapping#heat#to#allow#water#to#exist#as#a#liquid#

Other#gases#in#the#atmosphere#include#methane,,water,vapor,#and#ozone.,,,#Ozone#is#a#form#of#oxygen#with,three,oxygen#atoms#in#each#molecule.####Ozone#in#the#ozone#layer#is#needed#to#block#harmful#ultraviolet,radia#on.###

•  The#amount#of#water,vapor,in#the#atmosphere#changes.###

•  The#weather#changes#as#a#result#of#the#change#in#water#vapor.##

#Carbon#dioxide,#methane,#and#water#vapor#are#greenhouse,gases.##Greenhouse#gases#are#responsible#for#trapping#heat.##These#gases#are#needed#to#keep#our#planet#warm#enough#so#that#water#can#exist#as#a#liquid,or,gas.#

Share#your#answers!#

•  Why#do#we#need#the#ozone#layer?#

#•  Why#do#we#need#carbon#dioxide?#

With#your#group,#answer#the#following#quesJon…#

Using,the,two,graphs,,describe,how,the,atmosphere,has,changed,over,#me.,#Write#your#group’s#response#on#the#piece#of#handout#with#the#graphs.####AYer#3#minutes,#your#group#will#play#rock,#paper,#scissors.##The#group#winner#must#stand#to#share#your#group’s#ideas.#