Potassium (K): 1s22s22p63s23p64s1 core electrons and valence electrons
The Correct Answer and Explanation is:
To determine the core electrons and valence electrons of potassium (K), we need to analyze its electron configuration, which is:
1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹
Core Electrons:
Core electrons are those electrons that are in the inner energy levels of the atom, not involved in bonding or reactions, and they are typically in the inner shells closest to the nucleus. These electrons are the ones filling the atomic orbitals from the first shell up to the one just before the outermost shell (valence shell).
For potassium (K), the electron configuration shows that it has:
- 1s²: Two electrons in the first shell.
- 2s² 2p⁶: Eight electrons in the second shell.
- 3s² 3p⁶: Eight electrons in the third shell.
These electrons (1s² 2s² 2p⁶ 3s² 3p⁶) are considered core electrons because they are in the inner shells and are not involved in chemical bonding. Potassium has 18 core electrons.
Valence Electrons:
Valence electrons are the outermost electrons in an atom, typically in the highest energy level or shell, and they are the ones that participate in chemical reactions and bonding. For potassium, its electron configuration ends with 4s¹, which indicates that the only electron in the fourth shell (the outermost shell) is the valence electron.
Therefore, potassium has 1 valence electron in the 4s orbital.
Summary:
- Core electrons: 18 (electrons in the 1s, 2s, 2p, 3s, and 3p orbitals)
- Valence electron: 1 (in the 4s orbital)
This electron configuration explains potassium’s chemical behavior. Potassium is highly reactive, particularly because it has a single valence electron that can be easily lost to form a positively charged ion (K⁺), leading to a stable electron configuration similar to that of noble gases.