electron configuration

Question

An atomic cation with a charge of +1 has the following electron configuration:1s22s22p63s23p63d14s1

Answer 1

I am assuming this question is asking you to identify the element.

To identify the element, we count the number of electrons since it will match the number of protons when the atom is neutral.

This is not a neutral atom so we need to find how many electrons there would be atom is neutral. A cation of +1 means that the atom has one LESS electron than the neutral atom. So we should count how many electrons are in the electron configuration and then add one.

1s²2s²2p⁶3s²3p⁶3d¹4s¹

The number of electrons can be found by adding the number in the exponents.

2 + 2 + 6 + 2 + 6 + 1 + 1 = 20

Adding the cation --> 20 + 1 = 21

21 on the periodic table is "Sc" which is scandium