(a)[2]
Define proton number.
(b(i))[2]
Complete the table so it shows the numbers of protons, neutrons and electrons in atoms of $^{24}_{12}\text{Mg}$ and $^{26}_{12}\text{Mg}$.
(b(ii))[1]
What term describes atoms of the same element, such as $^{24}_{12}\text{Mg}$ and $^{26}_{12}\text{Mg}$?
(b(iii))[2]
Explain why the chemical properties of $^{24}_{12}\text{Mg}$ and $^{26}_{12}\text{Mg}$ are identical.
(c)[4]
Complete the table to identify the atoms and ions that have the following numbers of protons, neutrons and electrons.
(d)[2]
State the electronic structure of the atom and ion below. Al ............ S$^{2-}$ ............