Pearson Edexcel International GCSE (9–1) · PHYSICS · Chapter
Radioactivity
46 practice questions
Topics covered
Practice questions
11–20 of 23 · Normal
Question 11
1 mark · Normal
Answer and check →Which statement best describes a stable isotope?
- A.It has too many neutrons for its number of protons.
- B.It has no neutrons in its nucleus.
- C.It has a balanced number of protons and neutrons.
- D.It has more electrons than protons.
Question 12
2 marks · Normal
Answer and see the solution →Explain how the presence of neutrons in the nucleus prevents the protons from repelling and breaking apart the nucleus.
Question 13
3 marks · Normal
Answer and see the solution →A student claims that all isotopes of hydrogen are equally stable. Use your knowledge of isotopes and nuclear forces to explain why this statement is not correct.
Question 14
3 marks · Normal
Answer and see the solution →Explain why heavy elements like uranium have more neutrons than protons in their most stable isotope.
Question 15
4 marks · Normal
Answer and see the solution →The table below gives information about three isotopes of lithium.
Properties of lithium isotopes Isotope Protons Neutrons Lithium-6 3 3 Lithium-7 3 4 Lithium-8 3 5 (a)[1 mark]State, for all isotopes of lithium, what determines that they are all lithium atoms.
(b)[3 marks]Explain what effect increasing the number of neutrons has on the stability of the lithium nucleus. Use examples from the table.
Question 16
3 marks · Normal
Answer and see the solution →A student investigates two isotopes of boron: boron-10 and boron-12. Boron-10 is stable, but boron-12 decays quickly after it is produced.
Explain, in terms of neutrons and protons, why boron-12 is less stable than boron-10.
Question 17
1 mark · Normal
Answer and check →Which situation is most likely to make a nucleus unstable?
- A.Too few neutrons relative to protons
- B.More protons than neutrons
- C.A balanced number of neutrons and protons
- D.No protons in the nucleus
Question 18
4 marks · Normal
Answer and see the solution →Radon-222 is a radioactive gas found in some rocks. It decays by emitting an alpha particle.
(a)[1 mark]Complete the nuclear equation for this alpha decay:
(b)[1 mark]How do the atomic number and mass number of the daughter nucleus compare to those of the radon nucleus after the alpha emission?
(c)[1 mark]Radon-222 is an isotope of radon. State what is meant by the term isotope.
(d)[1 mark]Explain, in terms of neutrons and protons, why some isotopes, like radon-222, are radioactive.
Question 19
4 marks · Normal
Answer and see the solution →Potassium-40 is an unstable isotope present in the human body. Its nucleus can decay by emitting a beta minus particle, turning into calcium-40.
(a)[2 marks]Write a balanced nuclear equation for this beta minus decay. Supply all atomic numbers and mass numbers.
(b)[1 mark]Describe the changes in the atomic number and mass number that occur in the nucleus during this decay.
(c)[1 mark]Explain why potassium-40 is unstable in terms of neutrons and nuclear stability.
Question 20
5 marks · Normal
Answer and see the solution →An isotope of sodium, , is unstable and decays by emitting a beta minus () particle.
(a)[2 marks]Write the balanced nuclear equation for this decay, including the correct atomic and mass numbers for the product nucleus and the beta particle.
(b)[1 mark]Explain what happens to the atomic number and mass number of the nucleus during beta minus decay.
(c)[2 marks]Is the product nucleus more stable after the decay? With reference to neutrons and protons, explain your answer briefly.