1Which of these metals is harmful to our body? Fe, Ca, Zn or Pb?
2What is the poisonous effect of mercury called: hydrargyria, anaemia, haemophilia or scurvy?
3Why should children not be allowed to keep a mercury thermometer in their mouth?
4Write two harmful effects each of mercury and lead on the human body.
5List the sources of iron (Fe), zinc (Zn), sodium (Na) and potassium (K) needed by the human body.
6Why does a lack of iron cause anaemia?
7Give two jobs sodium does in the body and two effects of its deficiency.
8How does potassium help the bones and kidneys, and what does its deficiency do to blood pressure?
9Why is lead more dangerous for children, and what happens when lead collects in the bones?
10Write any four signs of zinc deficiency.