Same chapter2 marksDifficulty: Easy
Define the half-life of a radioactive substance.
Radioactivity
2 marksDifficulty: Easy
Name the three kinds of radiation emitted by radioactive substances and state the nature of each.
Original Khojo Papers practice question — not from a past board paper.
Answer
Alpha radiation consists of helium nuclei, each carrying a charge of +2e. Beta radiation consists of fast-moving electrons, each carrying a charge of −e. Gamma radiation consists of electromagnetic waves of very short wavelength and carries no charge.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
All three come from the nucleus, not from the electron shells.
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