3.2.1.2 Stable and unstable nuclei

The graph of neutron number against proton number shows three nuclei P, Q and R.

Which row identifies an isotope of P and the nucleon number of this isotope of P?

• Isotope of P: Q Nucleon number of isotope of P: y+1

• Isotope of P: Q Nucleon number of isotope of P: x+ y+1

• Isotope of P: R Nucleon number of isotope of P: x+ y+1

• Isotope of P: R Nucleon number of isotope of P: x+1

U-236 (Z=92) undergoes a series of decays to produce Pb-204 (Z=82).

How many alpha decays are involved in this decay series?

• 5

• 6

• 8

• 10

An iodine nucleus decays into a nucleus of Xe−131, a beta-minus particle and particle Y.

Which is a property of particle Y?

• It has a lepton number of +1

• It is an antiparticle

• It is negatively charged

• It experiences the strong interaction

When a nucleus of the radioactive isotope Ni-65 (Z=28) decays, a β^– particle and an electron antineutrino are emitted.

How many protons p and neutrons n are there in the resulting daughter nucleus?

• p=28, n=65

• p=29, n=65

• p=29, n=36

• p=30, n=35

Th-232 (Z=90) is an unstable nuclide in a radioactive decay series. It decays by emitting an α particle. The next two nuclides in the series emit β− particles.What nuclide is formed after these three decays have taken place?

• ²³⁰₉₀Th

• ²²⁸₉₂U

• ²²⁸₈₈Ra

• ²²⁸₉₀Th

Which sequence of radioactive emissions results in the formation of an isotope of the original element?

• one α particle and one β⁻ particle

• one α particle and two β− particles

• two α particles and one β− particle

• two α particles and two β− particles

A radioactive nucleus emits a β^–. particle then an α particle and finally another β^–. particle. The final nuclide is

• an isotope of the original element

• the same element with a different proton number

• a new element of higher proton number

• a new element of lower nucleon number

A nucleus of a particular element decays, emitting a series of α and β− particles.

Which of the following series of emissions would result in an isotope of the original element?

• 1 α and 1 β⁻

• 1 α and 2 β⁻

• 2 α and 1 β⁻

• 2 α and 2 β⁻