Answer:
It is not a pure substance.
The oxidation state is zero for Fe (s)
Answer:
Rb > K > Na > Li
Explanation:
Ionization energy increases up the period and up the group.
From the periodic table, we can see that Li is the going to have the highest ionization energy and Rb is going to have the lowest.
Therefore, the correct answer is the first choice
Why can't elements be separated into smaller parts using chemical means? Too much energy is required, since you'd have to break them down into protons, neutrons, and electrons. You can get this much energy together with nuclear reactions, but not by chemical means.
The correct answer of the given question above would be option C. Carbon dioxide absorbs the most heat energy during sublimation. It is the<span> transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase. Hope this answers your question.</span>