Question

How does electronic configuration of atoms change in a period with increase in atomic number? [2 MARKS]

Answer 1

Explanation: 2 Marks

On moving across a period from left to right, the atomic number of the elements increases. Therefore, the number of electrons in the valence shell increases from 1 to 8, i.e., the first element in the given period will have one electron in its valence shell and the last element in the same period will have eight electrons. In a period, the inner core shell remains same and the valence electrons in valence shell goes on increasing from left to right. The number of shells is same.