An element has a electron configuration of 1s2 2s2 2p6 3s2. Upon forming an ion, its new configuration is 1s2 2s2 2p6. Which is the ion formed?

1 Answer
Mar 12, 2018

You should swiftly be able to identify the parent element....

Explanation:

...why? Because you got 12 electrons...and if there are 12 electrons, 12 negative charges, the NEUTRAL element must contain 12 positive charges...i.e. Zatomic number=12...i.e. we gots Mg, the which commonly forms a Mg2+ ion as required for an alkaline earth....