Oxygen's valency is 2 because it needs to gain or share 2 electrons to be stable, like noble gases. Here's a simpler explanation:
Why Oxygen Needs 2 Electrons:
Electron Configuration:
- Oxygen has 8 protons and 8 electrons.
- These electrons are arranged in energy levels or shells.
- The outermost shell of oxygen can hold 8 electrons, but oxygen only has 6 in this shell.
Stable Electron Configuration:
- Noble gases like helium (He) and neon (Ne) are stable because their outer shells are full.
- Oxygen wants to be stable like noble gases, so it needs 8 electrons in its outer shell.
Gaining or Sharing Electrons:
- Oxygen needs 2 more electrons to fill its outer shell.
- It can gain these electrons or share them with other atoms.
Sharing Electrons:
- Oxygen often shares its electrons with other atoms to form covalent bonds.
- By sharing 2 electrons, oxygen can have 8 electrons in its outer shell, like it "borrowed" them.
Examples of Oxygen's Valency of 2:
Water Molecule (H₂O):
- Oxygen shares 2 electrons with 2 hydrogen atoms.
- This sharing fills its outer shell with 8 electrons.
Carbon Dioxide Molecule (CO₂):
- Oxygen shares 2 electrons with 2 carbon atoms.
- This sharing also fills its outer shell with 8 electrons.
Key Takeaway:
Oxygen's valency of 2 means it needs to gain or share 2 electrons to be stable. This lets oxygen form strong bonds with other elements, which is important for many molecules and compounds.
