Question

exam 2: periodicity & electron configuration/em spectrum
the element with a possible electron configuration of 1s²2s²2p⁶3s²3p⁶4s²3d³ is
o ca
o v
o cr
o as

Explanation:

Step1: Calculate the total number of electrons

Add up the electrons in each sub - shell. The number of electrons in $1s^2$ is 2, in $2s^2$ is 2, in $2p^6$ is 6, in $3s^2$ is 2, in $3p^6$ is 6, in $4s^2$ is 2, and in $3d^3$ is 3. So, $2 + 2+6 + 2+6 + 2+3=23$.

Step2: Identify the element based on atomic number

The atomic number of an element is equal to the number of electrons in a neutral atom. The element with atomic number 23 is Vanadium (V).

Answer:

B. V