State the electronic configuration of sulfur.
Predict polonium’s density.
Sulfur has a boiling point of $445\,^{\circ}\text{C}$. Predict the physical state of sulfur at $200\,^{\circ}\text{C}$. Explain your answer.
Draw the dot-and-cross diagram for a molecule of oxygen. Show only the outer shell electrons.
Explain, in terms of structure and bonding, why oxygen has a low melting point.
Deduce the formula for selenium(IV) oxide.
A small sample of selenium(IV) oxide is dissolved in water. Two drops of universal indicator are added to this aqueous solution. Predict the colour shown by the universal indicator in this solution. Explain your answer.
Calculate the volume, in dm$^3$, occupied by 30.2 g of oxygen at room temperature and pressure. Give your answer to two significant figures.