Imagine that NASA discovered a new planet with an atmosphere rich in hydrogen gas, hydrogen sulfide, ammonia and methane. We would call this a(n)

Question

A.  reducing atmosphere, because of the availability of hydrogen atoms that can donate electrons.
B.  reducing atmosphere because the atmosphere would reduce the energy necessary to build molecules.
C.  oxidizing atmosphere because of the availability of oxygen compounds.
D.  oxidizing atmosphere because of the lack of oxygen gas.

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
 
Gather Content
· What do you already know about the reducing atmosphere of the early earth?

  Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
 
Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

A.  reducing atmosphere, because of the availability of hydrogen atoms that can donate electrons.

Clarify Question
· What is the key concept addressed by the question?
        o This question addresses the reducing atmosphere of the early earth.
· What type of thinking is required?
        o This question is asking you to take what you already know and apply it to this unfamiliar situation.
 
Gather Content
· What do you already know about the reducing atmosphere of the early earth?
        o One view of the early atmosphere of the earth is that in addition to carbon dioxide, nitrogen gas, and water vapor, it also contained hydrogen gas, hydrogen sulfide, ammonia, and methane.
        o We refer to such an atmosphere as a reducing atmosphere because of the ample availability of hydrogen atoms and their electrons.

  Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o An atmosphere full of hydrogen is a reducing atmosphere, because hydrogen can donate electrons to other molecules – in chemical terms, it can reduce them.
        o This reducing atmosphere also serves to lower the energy needed to create larger molecules. But this is not why it is called a reducing atmosphere.
 
Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o The question required you to take what you already know and apply it to this unfamiliar situation.
        o Did you recognize that an atmosphere rich in hydrogen gas is a reducing atmosphere, because hydrogen can donate electrons, or “reduce”, other compounds?