Question

Which of the following happens when rubidium forms an ion?. A. It gains an electron and has an octet in its outer shell.. . B. It gains an electron and has an octet in the lowest energy level.. . C. It loses an electron and has an octet in the next-lowest energy level.. . D.It loses an electron and has an octet in its innermost shell.

Answer 1

The correct answer is letter D. When rubidium forms an ion, it loses and electron and has an octet in its innermost shell. I hope this has answered your question.

Answer 2

Rubidium is an alkali metal (a Group 1A metal). Therefore, its outermost energy level only contains one single electron. For it form an ion, it can lose that electron, meaning that its new outermost level will be one lower. In that next-lowest energy level, it has a full octet of electrons.
Therefore the best answer is D.