Atomic structure: Practice Questions

Which equation correctly represents the third ionisation energy of aluminium?

Which of the following elements has the highest second ionisation energy?

In a time-of-flight (TOF) mass spectrometer, singly charged ions of two isotopes of an unknown element, \(^{A}\text{X}^+\) and \(^{32}\text{S}^+\), are accelerated to have identical kinetic energies.
The \(^{32}\text{S}^+\) ion takes \(1.20 \times 10^{-5}\text{ s}\) to reach the detector.
The \(^{A}\text{X}^+\) ion takes \(1.50 \times 10^{-5}\text{ s}\) to travel the same distance under identical conditions.
What is the mass number \(A\) of the isotope \(^{A}\text{X}^+\)?

What is the maximum number of electrons that can occupy the principal quantum shell \(n = 3\)?

A sample of magnesium contains three isotopes: \(^{24}\text{Mg}\), \(^{25}\text{Mg}\), and \(^{26}\text{Mg}\).
The relative isotopic abundances are \(79.00\%\) for \(^{24}\text{Mg}\) and \(10.00\%\) for \(^{25}\text{Mg}\), with the remainder being \(^{26}\text{Mg}\).
What is the relative atomic mass (\(A_r\)) of this sample of magnesium?

Write an equation, including state symbols, to represent the process corresponding to the third ionisation energy of aluminium.

A sample of neon contains three isotopes: \(^{20}\text{Ne}\) (abundance \(90.48\%\)), \(^{21}\text{Ne}\) (abundance \(0.27\%\)), and \(^{22}\text{Ne}\) (abundance \(9.25\%\)).
Calculate the relative atomic mass (\(A_r\)) of this sample to 2 decimal places.

In a time-of-flight (TOF) mass spectrometer, singly charged ions of \(^{40}\text{Ca}^+\) and an unknown isotope \(^Z\text{M}^+\) are accelerated to have the same kinetic energy.
The \(^{40}\text{Ca}^+\) ions have a flight time of \(9.50 \times 10^{-6}\text{ s}\) over a flight distance of \(1.20\text{ m}\).
The \(^Z\text{M}^+\) ions require \(1.425 \times 10^{-5}\text{ s}\) to travel the same distance.
Calculate the mass number, \(Z\), of the ion \(^Z\text{M}^+\).

(a) Define the term first ionisation energy of an element.
(b) Write an equation, including state symbols, to represent the third ionisation energy of sodium.
(c) Explain why the first ionisation energy of aluminium (\(Z = 13\)) is lower than that of magnesium (\(Z = 12\)).

A sample of copper metal is analysed using a Time of Flight (TOF) mass spectrometer.

(a) Explain how positive ions are formed in the electrospray ionisation method.
(b) A singly charged ion \(^{63}\text{Cu}^+\) is accelerated through a potential difference and reaches a kinetic energy of \(1.85 \times 10^{-15}\text{ J}\).
Calculate the velocity, in \(\text{m s}^{-1}\), of this single \(^{63}\text{Cu}^+\) ion.
(Avogadro constant \(L = 6.022 \times 10^{23}\text{ mol}^{-1}\); relative isotopic mass of \(^{63}\text{Cu} = 63.0\))
(c) Calculate the time taken, in seconds, for this \(^{63}\text{Cu}^+\) ion to travel down a drift tube of length \(1.50\text{ m}\).