Answer:
He2 molecule contains 4 electrons. Each atom gives 2 electrons in 1s orbitals. This way 2 (1s) orbitals combine to give 2 molecular orbitals viz. ... This indicates that there is no bond formation between 2 HE atoms and hence the He2 molecule does not exist.
Explanation:
Option 2, Br. I'll go over why all other three options are incorrect.
Option 1 - Krypton is a Noble gas, and so it doesn't need to accept electrons since it has an octet.
Option 3 and 4 - Both Calcium and Barium are alkaline earth metals, and give away electrons, since they only have 2.
-T.B.
Answer: D
Explanation:
A has more kg/mass than B