Oxygen is an essential element for all life forms on Earth. Its atomic number is:

The Correct answer is 8.

Key Points

• The atomic number of an element is defined as the number of protons present in the nucleus of its atom.
• Oxygen is a chemical element with the symbol O, and its atomic number is 8, meaning each atom of oxygen has 8 protons.
• Oxygen is an essential element for life on Earth and makes up about 21% of Earth's atmosphere.
• It is highly reactive and forms compounds with almost all other elements, including water (H₂O) and carbon dioxide (CO₂).
• Oxygen is a member of the chalcogen group in the periodic table and is a non-metal.
• It exists as a diatomic molecule (O₂) in nature and is vital for the process of respiration in living organisms.
• Oxygen is also used in various industries, such as steel manufacturing, welding, and medical applications like oxygen therapy.

 Additional Information

• Incorrect Options
  • The atomic numbers 10, 12, and 6 do not correspond to oxygen. They represent different elements in the periodic table:
    • 10: Represents the element Neon, which is a noble gas.
    • 12: Represents the element Magnesium, which is an alkaline earth metal.
    • 6: Represents the element Carbon, which is a non-metal and a key element in organic chemistry.
• Importance of Oxygen
  • Oxygen is crucial for the process of aerobic respiration, which is how most organisms release energy from glucose.
  • It plays a key role in the Earth's carbon and water cycles.
  • The presence of oxygen in the atmosphere is largely due to photosynthesis, a process carried out by plants, algae, and cyanobacteria.
  • Oxygen is also essential for combustion, which is utilized in various industrial and domestic applications.