Help me pleas

Why are pairs of electrons discussed instead of individual electrons

Which statement describes the phase change that occurs when dry ice is placed in an open container at room temperature?

How many valence electrons are in atom of radon?

Problem page a jet airplane reaches 846. km/h on a certain flight. what distance does it cover in 13.0 min? set the math up. but don't do any of it. just leave your answer as a math expression. also, be sure your answer includes all the correct unit symbols.