What is the atomic symbol for the element that has 5 electrons in its outermost orbit, and has the smallest atomic mass of any element in its group?

Brainliesttt me asap! the below reaction can be categorized as more than one type of reaction. which reactions are these, and what are the types of reactions?

Which step in naming unsaturated hydrocarbons is used for alkenes but not alkynes

If a polyatomic ionic compound has gained two hydrogen ions, then how does its name begin?