How many p electrons does selenium (Se), atomic number 34, possess in its ground state?

• A. 12
• B. 6
• C. 18
• D. 10

Answer: (A)

Verified step by step guidance

1. Identify the electron configuration of selenium (Se) with atomic number 34. This means selenium has 34 electrons in its neutral ground state.
2. Recall the order of filling orbitals according to the Aufbau principle: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, etc.
3. Write the electron configuration for selenium step-by-step, filling orbitals until you reach 34 electrons:
4. \[1s^2\ 2s^2\ 2p^6\ 3s^2\ 3p^6\ 4s^2\ 3d^{10}\ 4p^4\]
5. Count the total number of electrons in all p orbitals (2p, 3p, and 4p) by adding the electrons in each p subshell: 2p^6 + 3p^6 + 4p^4.