Question

1. which electron configuration represents an excited state for a potassium atom? 2-8-7-2 2-8-7-1 2-8-8-2 2-8-8-1

Explanation:

The ground - state electron configuration of potassium (K) with atomic number 19 is 2 - 8 - 8 - 1. In an excited state, an electron moves to a higher - energy orbital. Option 2 - 8 - 7 - 2 shows an electron from the outermost shell (4s¹ in ground state) has moved to a higher - energy sub - shell, indicating an excited state.

Answer:

2 - 8 - 7 - 2