An excess of ……………. in plants and animals is toxic.

1. iron
2. magnetite
3. manganese
4. haematite

…………… is essential for plant growth and reduction of nitrates in green plants.

1. Mica
2. Iron
3. Manganese
4. Copper

Which of the following is a principal combination in which copper occurs in nature?

1. Sulphides
2. Oxides
3. Carbonate
4. All of the above.

…………… is a good conductor of electricity, highly malleable and ductile.

1. Copper
2. Iron
3. Bauxite
4. Mica