Pearson Edexcel International GCSE (9–1) · PHYSICS · Section
THE STABILITY OF ISOTOPES
20 practice questions
Practice questions
11–20 of 20
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 · Hard
Answer and see the solution →The isotope oxygen-19 has 8 protons and 11 neutrons. Oxygen-16 is a stable isotope. Explain, using scientific reasoning, why oxygen-19 is less stable than oxygen-16.
Question 19
5 marks · Hard
Answer and see the solution →A nucleus of potassium-40 () decays by emitting a beta minus particle to form a stable isotope.
(a)[2 marks]Write a balanced nuclear equation for this decay, including the atomic and mass numbers of all particles.
(b)[3 marks]Explain, using your answer, what has changed inside the nucleus.
Question 20
5 marks · Hard
Answer and see the solution →Explain, in detail, why nuclei with either far too few or far too many neutrons compared to protons tend to be unstable. In your answer, refer to the balance of forces in the nucleus and the typical changes that such nuclei might undergo to become more stable.