Critical Reasoning (CR) | Re: Spectroscopic analysis has revealed the existence of frozen nitrogen

Understanding the argument -
Spectroscopic analysis has revealed the existence of frozen nitrogen, methane, and carbon monoxide on the surface of Pluto. - Fact
Such ices have a tendency to vaporize, producing an atmosphere. - Fact
Since the proportion of any gas in such an atmosphere depends directly on how readily the corresponding ice vaporizes, astronomers have concluded that the components of Pluto's atmosphere are nitrogen, carbon monoxide, and methane, in order of decreasing abundance. - Supporting premise + Conclusion.
The supporting premise talks about "any gas," and the conclusion talks about three gases: "nitrogen, carbon monoxide, and methane, in order of decreasing abundance."

The minimum condition, missing premise, or the assumption is that there is no other material or gas. If there is any other material or gas, then the conclusion "the components of Pluto's atmosphere are nitrogen, carbon monoxide, and methane, in order of decreasing abundance"
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Statistics : Posted by Raman109 • on 14 Mar 2005, 00:39 • Replies 16 • Views 17808

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