The formula of the compound formed between a trivalent metal, M and a divalent non-metal, Y is

An atom of an element X gains two electrons. The symbol of the ion formed is

Which of the following statements is correct?

Which of the following arrangements represents the correct order of electronic energy level?

The element with electron configuration 1s\(^2\) 2s\(^2\) 2p\(^6\) 3s\(^2\) 3p\(^1\) belongs to