To determine where the valence electrons for Selenium (Se) are placed, we need to consider its electron configuration. Let's go through the step-by-step process to find this out.
1. Identify Selenium's Atomic Number:
Selenium (Se) has an atomic number of 34. This means it has 34 electrons when it is in its neutral state.
2. Write the Full Electron Configuration:
The full electron configuration for Selenium (Se) can be written by filling up the orbitals according to the Aufbau principle, Hund’s rule, and the Pauli exclusion principle:
- 1s²: 2 electrons
- 2s²: 2 electrons
- 2p⁶: 6 electrons
- 3s²: 2 electrons
- 3p⁶: 6 electrons
- 4s²: 2 electrons
- 3d¹⁰: 10 electrons
- 4p⁴: 4 electrons
So, the electron configuration for Selenium (Se) is:
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁴
3. Identify the Valence Electrons:
Valence electrons are the electrons in the outermost shell of an atom. For Selenium, the outermost shell is the fourth shell (4s² 4p⁴).
4. Determine Valence Orbitals:
The valence electrons of Selenium are those in the 4s and 4p orbitals.
Therefore, the valence electrons for Selenium (Se) are placed in the s orbital and p orbital.
So, the correct answer is:
- s orbital and p orbital
