(a)[1]
Draw the dot-and-cross diagram showing the bonding in a molecule of carbon dioxide. Include only the outer-shell electrons.
(b(i))[1]
State a single source of both ammonium nitrate and calcium phosphate.
(b(ii))[3]
Describe and explain the effect on the environment of these dissolved compounds in river water.
(c)[3]
Describe three processes used to purify river water.
(d(i))[1]
Explain why water melts at a low temperature.
(d(ii))[1]
Describe another method a student could use to confirm that water is neutral.