What is the lowest number energy level where a d sublevel is found

n = 3

Step-by-step explanation:

A d subshell has a secondary quantum number, l = 2.

The allowed values for l are 0, 1, 2, 3, ... n - 1.

We can write this mathematically as

l ≤ n - 1 Add 1 to each side

l + 1 ≤ n Reverse the inequality

n ≥ l + 1

Thus, if l = 2, n ≥ 3

Thus, the lowest energy level where you can find a d subshell is n = 3.