Atomic Structure and the Periodic Table: Practice Questions

Which sub-shell is being filled by the elements in the d-block of the Periodic Table?

The mass spectrum of an element shows two peaks: one at \( m/z = 63 \) with an abundance of \( 69.2\% \) and another at \( m/z = 65 \) with an abundance of \( 30.8\% \). What is the relative atomic mass of this element to one decimal place?

The first six successive ionisation energies (IE) of an element Y (in \(\text{kJ mol}^{-1}\)) are:

\(789, 1577, 3232, 4356, 16091, 19805\)

What is the formula of the most likely chloride formed by element Y?

What is the total number of electrons in a single \( ^{27}_{13}Al^{3+} \) ion?

Successive ionisation energy data for an element show a large jump between the second and third ionisation energies. Which group of the Periodic Table does this element belong to?

Define the term first ionisation energy as it applies to an element.

The table shows the first five successive ionisation energies of an element in Period 2 of the Periodic Table.

1st: \( 1086 \text{ kJ mol}^{-1} \)
2nd: \( 2353 \text{ kJ mol}^{-1} \)
3rd: \( 4621 \text{ kJ mol}^{-1} \)
4th: \( 6223 \text{ kJ mol}^{-1} \)
5th: \( 37831 \text{ kJ mol}^{-1} \)

Identify the element and justify your answer by referring to the electronic structure of the atom.

The first four successive ionisation energies of a Period 3 element are \( 578, 1817, 2745 \), and \( 11577\text{ kJ mol}^{-1} \). Identify the element and justify your choice based on the electronic structure evidence provided by these values.

A sample of magnesium contains three stable isotopes: \( ^{24}Mg \), \( ^{25}Mg \), and \( ^{26}Mg \).

(a) State the number of protons and neutrons in an atom of \( ^{25}Mg \).
(b) A mass spectrometer was used to analyze a sample of magnesium. The relative abundances were found to be: \( ^{24}Mg = 78.99\% \), \( ^{25}Mg = 10.00\% \), and \( ^{26}Mg = 11.01\% \). Calculate the relative atomic mass of this sample of magnesium to two decimal places.
(c) Explain why the chemical properties of these three isotopes are identical.

This question is about elements in Period 3 of the Periodic Table.

(a) Write an equation, including state symbols, to represent the second ionisation energy of sodium.

(b) Explain why the first ionisation energy of aluminium is lower than the first ionisation energy of magnesium.

(c) Explain why the first ionisation energy of sulfur is lower than the first ionisation energy of phosphorus.

(d) Give the full electronic configuration of the phosphide ion, \( \text{P}^{3-} \), using \( s, p, d \) notation.