Argon is produced in Earth’s crust via?

Correct option is A

The correct answer is (a) Decay of K-40.
• Argon-40 is produced by the radioactive decay of Potassium-40 (K-40) present in Earth’s crust.
• It contributes significantly to atmospheric argon.
Information Booster
• Potassium-40 has a half-life of ~1.25 billion years.
• Argon makes up about 0.93% of Earth’s atmosphere.
• Used in radiometric dating (K–Ar dating).
• Argon is a noble gas (Group 18).
Additional Knowledge
• K–Ar dating is used for volcanic rocks.
• Argon is chemically inert.
• Earth’s atmosphere contains more argon than Mars or Venus.
• Noble gases are monoatomic and non-reactive.