Uranium-238 () decays by emitting an alpha particle. What are the mass number and atomic number of the daughter nucleus?
Answer and explanation
Correct answer: D. mass number , atomic number
- Step 1: An alpha particle is a helium nucleus, .
- Step 2: Mass number: . Atomic number: .
Answer
mass number , atomic number .
Why not the others: mass number , atomic number : loses only one proton. mass number , atomic number : describes beta-minus decay, not alpha. mass number , atomic number : loses only two nucleons.
Practise more Radioactivity and nuclear physics.
Free questions with an explanation for every one, and full timed ESAT (Engineering and Science Admissions Test) mock tests.
More Radioactivity and nuclear physics questions
- The activity of a source falls from to in days. What is its half-life?
- Carbon-14 () undergoes beta-minus decay. Which nucleus is formed?
- A radioactive isotope has a half-life of hours. What fraction of the original nuclei remains after hours?
- A sample contains of a radioactive isotope. After three half-lives how much of the isotope remains?
- Which type of radiation is stopped by a sheet of paper?