Nuclear Chemistry and Radioactivity Quiz

Grade 12 · Science · Quiz

Test your knowledge of radioactive decay, half-life calculations, nuclear reactions, and applications.

Questions

If a sample has a half-life of 10 years, what fraction remains after 30 years?
1. 1/2
2. 1/4
3. 1/8
4. 1/16
Show answer
Answer: 1/8
30 years = 3 half-lives. After each half-life the amount halves: 1 → 1/2 → 1/4 → 1/8. The formula is (1/2)^n where n = number of half-lives.
Nuclear reactions release more energy per gram than chemical reactions.
Show answer
Answer: True
Nuclear reactions involve changes in nuclear binding energy and convert mass to energy via E = mc². The energy per gram is millions of times greater than chemical reactions.
Carbon-14 dating is based on the predictable ___ of carbon-14 in dead organisms.
Show answer
Answer: decay
Living organisms maintain constant C-14 levels by absorbing carbon from the environment. At death, C-14 decays at a known rate (half-life ~5,730 years), allowing age estimation.
Which particle is emitted in beta-minus decay?
1. Proton
2. Neutron
3. Electron
4. Positron
Show answer
Answer: Electron
In beta-minus (β⁻) decay, a neutron converts to a proton and emits a high-energy electron (beta particle) and an antineutrino.
In nuclear fission, the total mass of products is slightly greater than the mass of the original nucleus.
Show answer
Answer: False
In fission, the total mass of products is slightly LESS than the original nucleus. The 'missing' mass (mass defect) is converted to energy per E = mc².
Which type of radiation is stopped by a sheet of paper?
1. Beta particles
2. Gamma rays
3. Alpha particles
4. X-rays
Show answer
Answer: Alpha particles
Alpha particles are large (2 protons + 2 neutrons) and positively charged, so they interact strongly with matter and are easily stopped by paper or a few centimeters of air.
Einstein's equation E = ___ describes mass-energy equivalence.
Show answer
Answer: mc²
E = mc² where E is energy, m is mass, and c is the speed of light (~3 × 10⁸ m/s). Even tiny mass converts to enormous energy because c² is a very large number.
Radioactive half-life increases as temperature increases.
Show answer
Answer: False
Half-life is a nuclear property determined by the strong and weak nuclear forces, completely independent of temperature, pressure, or chemical state.
In a nuclear reactor, control rods are used to:
1. Increase the fission chain reaction
2. Absorb neutrons and control the reaction rate
3. Fuel the reactor
4. Cool the reactor core
Show answer
Answer: Absorb neutrons and control the reaction rate
Control rods in nuclear reactors are made of neutron-absorbing materials (boron, cadmium). Inserting them slows the fission chain reaction; withdrawing them allows it to proceed faster.
What happens to the atomic number during beta-minus decay?
1. Increases by 1
2. Decreases by 1
3. Decreases by 2
4. Stays the same
Show answer
Answer: Increases by 1
In β⁻ decay, a neutron becomes a proton, increasing the atomic number by 1 while the mass number stays the same (total nucleons unchanged).

Get a personalized course on Nuclear Chemistry and Radioactivity built around your child.