<u>Answer:</u>
Carbon and silicon both are tetravalent elements as compared to germanium, tin, and lead which are divalent.
That's because Ge, tin, and Pb show inert pair effect and has a greater nuclear effective charge on the 's' electrons due to poor shielding effect. .That's why these elements are not able to share their valence electrons while carbon and silicon does and show "catenation" which is the ability to form long chain molecules.
A.)Neutral. Since amount of protons and electron are equal and amount of protons cannot be changed so it is stable or neutral.
<span>The best reason I can think of for why we believe that air is a mixture is that freezing air slowly yields different liquids at different temperatures. Liquid nitrogen has a different boiling point than liquid oxygen. They also freeze at different temperatures. If air were only 1 compound, then air in its entirety would have a single boiling point and a single freezing point. </span>
Explanation:
solution has a pH of 2 is a strong acid.