How many valence electrons does oxygen have? (atomic number=8)
The correct answer and explanation is :
Oxygen has 6 valence electrons.
To understand why, let’s break it down:
Atomic Structure of Oxygen:
Oxygen has an atomic number of 8, meaning it has 8 protons and 8 electrons in a neutral atom. The electron configuration of oxygen is:
- 1s² 2s² 2p⁴
This tells us that oxygen’s electrons are arranged in two energy levels (shells):
- The first shell (1s) holds 2 electrons.
- The second shell (2s and 2p) holds 6 electrons in total (2 in 2s and 4 in 2p).
What are Valence Electrons?
Valence electrons are the electrons found in the outermost shell (energy level) of an atom. These electrons are important because they are involved in chemical bonding, determining how an atom will react with others to form compounds.
Why Does Oxygen Have 6 Valence Electrons?
Looking at the electron configuration, oxygen has 6 electrons in its outermost shell (the second shell, with the 2s and 2p orbitals). Therefore, these 6 electrons are the valence electrons.
The valence electrons in an atom dictate its chemical behavior. For oxygen, with 6 valence electrons, it needs to gain 2 more electrons to complete its outer shell and achieve a stable electron configuration similar to that of the nearest noble gas, neon. This is why oxygen often forms bonds by sharing electrons, such as in water (H₂O) and many other compounds, where it typically forms two bonds to satisfy the octet rule.
In summary, oxygen has 6 valence electrons because its electron configuration ends in the second energy level, with 2 electrons in the 2s orbital and 4 electrons in the 2p orbital, making it highly reactive and able to form strong bonds with other elements.