Question

3. An element “X” has mass number 35 and the number of neutrons, is 18. Identify the

group number and period of “X”.

Answer 1

Group number 17 and period is 3

Answer 2

Mass no-35
no. of neutrons-18
no. of protons=Mass no. - No. of neutrons
=35-18=17
therefore the number of electrons in the element is also 17.
therefore the element belongs to group 17 and period 3. the element X is actually chlorine. hope it helps you happy new year and please mark my answer as the brain list if you like it.