Answer: Option (a) is the correct answer.
Explanation:
We know that ground state means in total electrons acquired by the element are present in their lowest energy level.
We calculate the azimutal numbers as follows.
n = l + 1
where, n = principle quantum number
l = azimuthal quantum number
Values of n can be 1, 2, 3, 4 and so on. Whereas the values of l can be 0, 1, 2, 3, and so on.
Also, "m" is known as magnetic quantum number whose values can be equal to -l and +l.
So, when n = 1 then l = 0 and m = 0.
When n = 2 then l = 1 and values of m will be equal to -1, 0, +1. As it is given that the magnetic quantum number ml = -1. Hence, it is only possible when n = 2.
And, n = 1 is the lowest energy level. Therefore, we can conclude that the ground state of an atom means all of the quantum numbers have their lowest values (n = 1,ℓ = mℓ = 0).
