Exam-style Questions: Radioactivity

  1. a) What is ionising radiation?

    (1 mark)

    b) Why is ionising radiation dangerous to living tissue?

    (1 mark)

    c) Why is alpha radiation particularly dangerous if ingested?

    (1 mark)

    (Marks available: 3)

  2. The radioactive nuclide, 23992U, decays by alpha-particle emission. The newly formed nuclide X is also unstable and decays by a different radioactive emission to a third nuclide Y. Y then decays to become another isotope of uranium 23492U.

    a) Explain the meaning of the term isotope.

    (1 mark)

    b) Write down suitable symbols in the form 23992U for

    an α-particle ......................

    a β-particle..........................

    (2 marks)

    c) Show how 23992U can become the isotope 23492U after three decays.

    (3 marks)

    (Marks available: 6)

  3. The equation shows a possible neutron-induced fission for a nucleus of plutonium-239.

    Copyright S-cool

    How many neutrons are emitted?

    number of neutrons = ...................

    (1 mark)

Answer

Answer outline and marking scheme for question:

  1. a) Radiation capable of ionising atoms.

    (1 mark)

    b) The charged particles/ions produced can interfere with biological processes.

    (1 mark)

    c) Alpha radiation is highly ionising if inside the body it can easily damage internal tissue.

    (1 mark)

    (Marks available: 3)

  2. a) An element can exist in more than one form, having a different number of neutrons /can have different mass but same proton number / AW

    (1 mark)

    b) 42He / 42α ; (-) 0-1e / 0-1β

    (2 marks)

    c) 23892U →23492U + 42α + 0-1β + 0-1β

    or 23892U→ 23490X + 42α

    23490X→ 23491Y + 0-1β

    23491Y→23492U + 0-1β

    (3 marks)

    (Marks available: 6)

  3. Six

    (1 mark)