Give the equation, with state symbols included, for the first ionisation energy of carbon.
Explain why sodium has a lower first ionisation energy than magnesium.
Explain why magnesium has a higher first ionisation energy than aluminium.
Explain why helium, $\text{He}$, and neon, $\text{Ne}$, are positioned at the top two places on the diagram.
Explain why the first ionisation energy of argon, $\text{Ar}$, is lower than that of neon, which is lower than that of helium.
The first ionisation energies of the elements Na to Ar show a variation. Some physical properties show similar changes. The atomic radius of the elements decreases from Na to Cl. Give a brief explanation of this variation.
The cations formed by the elements Na to Al are smaller than the corresponding atoms. Give a brief explanation of this change.
The oxides of the elements of the third Period behave in different ways with $\text{NaOH}_{(aq)}$ and $\text{HCl}_{(aq)}$. In some cases, there is no reaction. Complete the table by writing a balanced equation for any reaction that occurs, with heating if needed. If you think no reaction takes place write "no reaction". You do not need to include state symbols in your answers.