An element has same number of electrons in I and IV shells and in the II and III shells
i] Write its electronic configuration
ii] Write the group and period it belong
iii] What is the valency of the element

Explanation

i] Electronic configuration `{:(K,L,M,N),(2,8,8,2):}`
ii] Group 2 [because valence shell contains 2 electrons] period 4th (as the number of shells are 4]
iii] Valency of the element is 2.