The structure of an atom

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.

Which nuclear change results in the nucleus with the greatest specific charge?

A nucleus contains N neutrons and Z protons.

Which combination of N and Z gives a nucleus with the greatest specific charge?

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.

What is the specific charge of a 136 C nucleus?

The current in a metallic conductor is 1.5 mA.

How many electrons pass a point in the conductor in two minutes?

Cosmic rays are high-energy particles that come from space. Most of these particles are protons. There are other particles in cosmic rays, including atomic nuclei.

Table 1 gives the data for one particular nucleus X.

Determine the number of neutrons in nucleus X.

Calculate the speed of X. Ignore relativistic effects.

A pion (π⁺) and a kaon (K⁺) are produced when cosmic rays interact with the upper

atmosphere.

The π⁺ decays to produce a positron and an electron neutrino.

Show how the conservation laws apply to this decay.

The K⁺ decays to produce an anti-muon and a muon neutrino.

Explain how strangeness applies in this decay.

Write an equation for a K⁺ decay that involves only hadrons.

A deuterium nucleus and a tritium nucleus fuse together to produce a helium nucleus and particle X.

2 3 4

What is X ?

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.

Fluoride ions are produced by the addition of a single electron to an atom of fluorine¹⁹₉F.

What is the magnitude of specific charge of the fluoride ion?

What is the specific charge of the ion?