An atom has electronic configuration $2 s^2$ $2 p^6 3 s^2 3 p^6 3 d^3 4 s^2$, in which group it will be…
An atom has electronic configuration $2 s^2$ $2 p^6 3 s^2 3 p^6 3 d^3 4 s^2$, in which group it will be placed?
Fifth
Fifteenth
Second
Third
Solution
Since the $3 d$ contains 3 electrons, thus the given elements is Vanadium, which is placed in $5^{\text {th }}$ group and $4^{\text {th }}$ period.
The number of each period represents the number of energy levels that have electrons in them for atoms of each element in that period. The group number in the periodic table represents number of valence electrons of the elements in a certain group.