Answer to Question #149350 in Chemistry for AFOLABI Omoshalewa

Question

Without referring to the periodic table,name the elements,give their electronic structure and name the group in the periodic table to which the following atomic number belong
3,9,12,17,20

Answer 1

Atomic number 3 - Lithium 1s²2s¹, group 1

Atomic number 9 - Fluorine 1s²2s²2p⁵, group 17

Atomic number 12 - Magnesium, 1s²2s²2p⁶3s², group 2

Atomic number 17 - Chlorine, 1s²2s²2p⁶3s²3p⁵, group 17

Atomic number 20 - Calcium, 1s²2s²2p⁶3s²3p⁶4s², group 2