Question

The electrons in the atoms of four elements A, B, C and D are distributed in three shells having 1, 3, 5 and 7 electrons in the outermost shell respectively. State the group in which these elements can be placed in the modern periodic table. Write the electronic configuration of the atoms of B and D and the molecular formula of the compound formed when B and D combine.

Answer 1

all the elements belong to 3 period

Electeonic confoguration of

A= 2,8,1

B=2,8,3

A is magnesium

B is chlorine

so when they combine

it forms magnesium chloride.(AD)

Thank you.....!!!!

Answer 2

Explanation:

Element No. of Valence Electronic configuration Group No. A 1 2, 8, 1 1 B 3 2, 8, 3 13 C 5 2, 8 , 5 15 D 7 2, 8, 7 17 Molecular formula of compound formed by B and D will be BD3