Atomic structure & radioactivity
Edexcel GCSE Physics revision on Atomic structure & radioactivity. Aligned to the Pearson Edexcel GCSE Physics 1PH0 specification. This bank has 18 practice questions on this topic.
Sample questions (3 of 18)
-
Question 1
In an alpha decay, the nucleus emits a particle made of...
- A) 2 protons + 2 neutrons (helium nucleus)
- B) 1 electron
- C) 1 photon
- D) 1 neutron
Show answer
Answer: 2 protons + 2 neutrons (helium nucleus)
Alpha particle = helium-4 nucleus. Effect on parent nucleus: mass number drops by 4, atomic number drops by 2 (changes element). Properties: heavy, charged +2, slow (~5% of c), HIGHLY ionising, but easily stopped (paper, skin, few cm of air). Dangerous if INSIDE the body (radon gas inhalation, ingested polonium).
-
Question 2
Beta-minus decay emits...
- A) A neutron
- B) A high-speed electron
- C) An alpha particle
- D) A gamma ray
Show answer
Answer: A high-speed electron
Beta-minus particle = high-speed electron from the nucleus. Inside the nucleus, a neutron transforms into a proton + an electron + an antineutrino. The new proton stays; the electron is ejected as beta radiation. Mass number unchanged; atomic number rises by 1 (a new element). Beta particles: charged -1, fast, MODERATELY ionising, stopped by ~3mm of aluminium. Carbon-14 dating uses beta decay (C-14 -> N-14).
-
Question 3
Gamma radiation is a...
- A) Particle
- B) High-energy electromagnetic wave (photon)
- C) Small atom
- D) Type of sound
Show answer
Answer: High-energy electromagnetic wave (photon)
Gamma rays are highest-frequency EM waves. Emitted from excited nuclei after alpha or beta decay. Properties: no mass, no charge, very penetrating (stopped only by thick lead or concrete), highly ionising. Used in: sterilisation, cancer treatment, gamma-ray imaging. The most penetrating radiation hazard - external + internal.
Want to test yourself on the remaining cards for this topic?
15 more questions on Atomic structure & radioactivity — plus mistakes tracking and spaced repetition across the whole Physics spec.