State what are metalloids. Name the elements recognized as metalloids. Compare the properties of metalloids with those of metals. State the uses of three different metalloids.

Explain the term – rusting and give a word equation for the formation of rust. If polished iron nails are kept in three separate test tubes, state the contents in each test tube required, to prove the conditions for rusting.

Give a reason why oiling or greasing is done on the exposed moving iron parts of machinery and not preferred on heavy stationary iron parts.

State why galvanization, tinning and chromeplating are used as three different processes for coating specific articles for prevention of rusting.