Name: _______________________ Date: _____________ Class period: ________


Student Worksheet
Lesson: Graphs and the Composition of Earth's Thermosphere

Directions: After reading the background information,
summarize the characteristics of the thermosphere in the space provided.
Summary of thermospheric characteristics. 


Directions: Study the graph, “Principal Constituents
of the Thermosphere” and complete the data tables.
Data Table #1

Constituent

Name

Describe what happens to the density as height
increases.

O



O_{2}



N



N_{2}



H



He



Directions: Refer to a Periodic Table of the Elements
and the graph, “Principal Constituents of the Thermosphere” as
you complete the information required in Data Table #2.
Data Table #2

Constituent

Atomic Mass
of Constituent

Maximum Density
(#/cm^{3})

Height of Maximum Density
(km)

O




O_{2}




N




N_{2}




H




He





Analysis Questions:
 The two variables being measured in the graph, “Principal
Constituents of the Thermosphere” are Height (km) and Particle
Density (#/cm^{3}). Which variable is the independent and which
is the dependent? (Remember the dependent variable “responds
as the independent variable is changed".)
 By convention, the independent variable is usually located on
the xaxis of a graph. Carefully observe the graph, “Principal
Constituents of the Thermosphere”. What do you notice about the
independent variable and dependent variable?
 Give a possible explanation for what you found in question #2.
 In the table provided below, rewrite the list of thermospheric
constituents in order of their atomic masses (smallest to largest).
 At what height(s) do the heavier constituents have their greatest density?
 At what height(s) do the lighter constituents have their greatest density?
 Give a possible explanation for what you found in questions 5 and 6.
 In the background, it was stated, “…scientists can’t
measure the temperature directly. They measure the density of the air by
how much drag it puts on satellites and then use the density to find the
temperature.” What are some possible reasons for the importance of
knowing the density and the temperature of the thermosphere?

Last modified May 27, 2005 by Randy Russell.
The source of this material is Windows to the Universe,
at http://www.windows.ucar.edu/ at the University Corporation for Atmospheric
Research (UCAR). © 2005 University Corporation for Atmospheric
Research. All Rights Reserved. 