Give the chemical symbol for the element with the ground‑state electron configuration [ ar ] 4 s 2 3 d 1 . symbol: determine the quantum numbers n and ℓ and select all possible values for m ℓ for each subshell of the element. 4 s n = 4 s ℓ = the possible values of m ℓ for the 4 s subshell are 0 − 1 , 0 , + 1 − 2 , − 1 , 0 , + 1 , + 2 − 3 , − 2 , − 1 , 0 , + 1 , + 2 , + 3 3 d n = 3 d ℓ = the possible values of m ℓ for the 3 d subshell are − 1 , 0 , + 1 − 2 , − 1 , 0 , + 1 , + 2 − 3 , − 2 , − 1 , 0 , + 1 , + 2 , + 3 0