Fundamental forces and exchange particles

This question is about an isotope of titanium that only decays by electron capture.

Complete Figure 1 to show the quark change that occurs during electron capture. Label the incoming and outgoing particles and the exchange particle.

In some circumstances, a nucleus of this isotope can exist with no orbiting electrons.

Explain why a neutral atom of this isotope is less stable than a nucleus that has no orbiting electrons.

A nucleus of this isotope of titanium has a proton number of 22 and a specific charge

Determine the number of neutrons in this nucleus.

State the names of the four fundamental interactions.

State the products of the decay of a free neutron.

Explain which of the fundamental interactions is responsible for the decay of the neutron.

The forces between two moving electrons cause their paths to change.

Explain, using the concept of exchange particles, why the electron paths change.

The neutral lambda particle Λ⁰ is a baryon with a strangeness of −1

One possible decay for a Λ⁰ is

Deduce the quark structure of a Λ⁰.

State and explain which interaction is involved in this decay.

An antiparticle of the neutral lambda particle decays into a neutral pion and particle X

Identify X.

The rest energy of a Λ⁰ is equal to the energy of a photon with a frequency

Determine, in MeV, the rest energy of a Λ⁰.

The discovery of particles such as the Λ⁰ is made by large international research teams.

Suggest one reason for this.

Two stable isotopes of helium are 42He and 32He.

An atom of 42He is produced in a rock that contains uranium. It is produced following 238 the radioactive decay of a 92U atom. The decay also creates an atom of thorium (Th).

238 Write an equation for the decay of 92U.

238

A 32He nucleus can be produced by the decay of a tritium nucleus 31H.

State and explain which exchange particle is responsible for this decay.

Helium was discovered by analysing the light in the absorption spectrum of the Sun.

Figure 1 shows the positions of the brightest lines, labelled A to F, in the emission spectrum of helium. The brightest lines in the emission spectra of sodium and hydrogen are also shown.

Before helium was identified, some scientists suggested that the lines of the helium spectrum seen in the absorption spectrum of the Sun were due to the presence of sodium and hydrogen.

Discuss, with reference to the lines A to F in Figure 1, the evidence for and against this suggestion.

Calculate, in eV, the change in energy level responsible for the spectral line labelled in Figure 1.

Explain, with reference to the processes within an atom, the difference between an emission spectrum and an absorption spectrum.

The gravitational force is one of the four fundamental forces. The ticks in the table match particles with the other fundamental forces.

In which row is the particle matched to the only other fundamental forces it experiences?

The diagram represents a particle interaction.

Which row identifies particles E, F and G ?

125 131 Two isotopes of iodine are I and I. 53 53

Determine, for these two isotopes, the difference between the constituents of the nuclei.

131 – A₅₃ I nuclide undergoes beta (β) decay to form a xenon nuclide.

State the nucleon number of the xenon nuclide.

125 A₅₃ I nuclide decays by electron capture to form a tellurium nuclide.

State two differences between the constituents of the iodine nucleus and the tellurium nucleus it decays into.

Internal conversion is a process in which a nucleus in an excited state can release its excess energy. In internal conversion all of the excess energy is transferred from the nucleus to an orbital electron through the electromagnetic force. This orbital electron is ejected from the atom.

The tellurium nucleus formed in question 01.3 is in an excited state and can undergo internal conversion.

Discuss three differences between internal conversion and beta (β^–) decay.

The decay is represented by this equation:

Complete the equation to show the decay by filling in the gaps.

Explain which fundamental interaction is responsible for the decay in question 01.1.

One decay mechanism for the decay of results in the argon nucleus having an excess energy of 1.46 MeV. It loses this energy by emitting a single gamma photon.

Calculate the wavelength of the photon released by the argon nucleus.

The potassium isotope can also decay by a second decay process to form a

Suggest how the emissions from a nucleus of decaying potassium can be used to confirm which decay process is occurring.