Question

Two elements A. and B have atomic number 12 and 17 respectively .Which element has two shells, both of which are completely filled with electrons?

Answer 1

Answer..None of them is completely filled

Explanation:

Atomic no 12 is magnesium which is having 2,8,2 and 17 chlorine with 2,8,7 chlorine needs 1 electron to complete its octet whereas magnesium will give away 2 electrons to make it stable.