The partial electron configuration of an atom with 14 electrons is shown. 1s22s2 2p63s2x which of the following does x represent? a. 2d2 b. 3s2 c. 3p2 d. 4s2

Given:

Atomic number of an atom = 14

Partial electron configuration = 1s²2s²2p⁶3s²X

To determine:

The identity of X

Explanation:

Based on the Aufbau rule, the order in which the orbitals fill up based on energetic considerations is:

1s 2s 2p 3s 3p 4s 3d 4p

maximum # electrons in s orbital = 2, p = 6,  d = 10 and so on

Since 3p would follow the 3s orbital, in this case we will have the full configuration as:

1s²2s²2p⁶3s²3p²

Ans c) X = 3p²

4d^55s^1 ( third choice)