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 period in which these elements can be placed in the modern periodic table. Write the electronic configuration of the atoms of a and d and the molecular formula of the compound formed when a and d combine.3

Answer 1

period is 3
electronic configuration of a=2,8,1
electronic configuration of d=2,8,7
compound formed by a and d =ad