Gallium has two stable isotopes, $^{69}\text{Ga}$ and $^{71}\text{Ga}$. Fill in Table 1.1 to indicate the numbers of protons, neutrons and electrons in gallium’s two stable isotopes.
Define the term relative atomic mass.
The relative atomic mass of gallium, $A_r$, is $69.723$. The relative isotopic masses of $^{69}\text{Ga}$ and $^{71}\text{Ga}$ are $68.926$ and $70.925$, respectively. Use this information to calculate the percentage abundance of $^{69}\text{Ga}$ in elemental gallium. Show your working. Assume that the element contains only the $^{69}\text{Ga}$ and $^{71}\text{Ga}$ isotopes. Give your answer to four significant figures.
Potassium has two stable isotopes as well. The two isotopes have identical chemical properties. Explain why the chemical properties are the same for both isotopes of potassium.
State the complete electronic configuration for an atom of potassium.
The first, second and third ionisation energies of potassium are $418$, $3070$ and $4600\ \text{kJ mol}^{-1}$, respectively. Use this information to explain why potassium belongs in Group $1$.