(a)[2]
State one way they differ and one way they are alike.
(b)[1]
Phosphorus makes simple molecules with a relative molecular mass of 124. Suggest the formula of a phosphorus molecule.
(c(i))[1]
Phosphorus has a low melting point and is a poor conductor of electricity. Explain why phosphorus has a low melting point.
(c(ii))[1]
Explain why phosphorus does not conduct electricity.
(d)[3]
Complete the table for $^{31}_{15}\text{P}^{3-}$ by giving the number of neutrons, number of protons and electronic configuration.
(e)[2]
Phosphorus forms a compound called phosphine, PH$_3$. Draw the dot-and-cross diagram to show the bonding in a molecule of phosphine. Show only the outer shell electrons.
(f)[2]
Phosphine burns in air to form water and phosphorus(V) oxide. Write the equation for this reaction.