Which statement describes a reason to consider air a mixture? a) the major constituents of air are gaseous elements. b) the components of air can be separated by chemical processes. c) the original chemical properties of all the components remain intact. d) the major constituent is nitrogen, which does not react with other components.

The correct answer is - A) The major constituents of air are gaseous elements.

With the statement ''the major constituents of air are gaseous elements'' we can easily conclude that the air is a mixture. The reason for that is that we have a plural usage of the word element, elements, which mean that there are multiple elements that make up the air.

The air is indeed predominantly a mixture of gaseous elements. The most abundant gas in the air being the nitrogen with 78.9%, oxygen with 20.95%, argon 0.93%, and carbon dioxide 0.04%, with lesser amounts of other gases also be present in it. The water vapor is also present in the air, though it is variable, being around 1% at sea level, but only 0.4% over the entire atmosphere.

i dont know

explanation:

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.