Physics Physics Nuclear Physics 2 — Questions and Answers
Question 1: What particle is emitted during alpha decay?
- A helium-4 nucleus (Correct answer)
- An electron
- A high-energy photon
- A neutron
Correct answer: A helium-4 nucleus
Alpha decay releases an alpha particle, which is a helium-4 nucleus consisting of 2 protons and 2 neutrons.
Question 2: In beta-minus decay, what is emitted from the nucleus?
- An electron (Correct answer)
- A positron
- A proton
- An alpha particle
Correct answer: An electron
In beta-minus decay, a neutron converts to a proton, emitting an electron (beta particle) and an antineutrino.
Question 3: What is the half-life of a radioactive isotope?
- Time for half of the radioactive atoms to decay (Correct answer)
- Time for an atom to complete one nuclear orbit
- Half the period of nuclear vibration
- Time for binding energy to decrease by half
Correct answer: Time for half of the radioactive atoms to decay
Half-life is the time required for exactly half of the radioactive atoms in a given sample to undergo radioactive decay.
Question 4: Gamma radiation consists of:
- High-energy electromagnetic photons (Correct answer)
- High-speed electrons
- Helium-4 nuclei
- Fast-moving neutrons
Correct answer: High-energy electromagnetic photons
Gamma rays are high-energy electromagnetic radiation (photons) emitted from the nucleus, often accompanying alpha or beta decay.
Question 5: Carbon-14 radiocarbon dating works because after an organism dies it:
- Stops absorbing carbon-14, which then decays at a known rate (Correct answer)
- Starts absorbing carbon-14 at an accelerated rate
- Converts carbon-12 to carbon-14 through decay
- Preserves a fixed ratio of all carbon isotopes indefinitely
Correct answer: Stops absorbing carbon-14, which then decays at a known rate
When an organism dies it stops incorporating carbon-14, which then decays at a known rate, allowing scientists to calculate the time since death.
Question 6: Which type of nuclear decay increases the atomic number by 1?
- Beta-minus decay (Correct answer)
- Alpha decay
- Gamma decay
- Beta-plus decay
Correct answer: Beta-minus decay
In beta-minus decay, a neutron transforms into a proton, increasing Z by 1 while the mass number A stays the same.
Physics Physics Nuclear Physics 2
What particle is emitted during alpha decay?