A graph of the first ionisation energies for the first $18$ elements is shown. Explain why the values display a general rise from atomic number $11$ to $18$.
Explain the falls in first ionisation energies between: - atomic numbers $12$ and $13$, - atomic numbers $15$ and $16$.
Suggest an explanation for the trend in the first ionisation energies of the elements with atomic numbers $2$, $10$ and $18$.
A graph of the melting points of the elements across the third period is shown. Explain the rise in melting point from atomic number $11$ to $12$.
Suggest a reason why the rise from atomic number $12$ to $13$ is much smaller than the rise from atomic number $11$ to $12$.
State and explain the pattern of the melting points from atomic number $15$ to $18$.
Explain why the element with atomic number $14$ has a melting point that is much higher than that of the rest of the elements in the third period.