Because it is covalent compound formed by sharing of electrons. Whereas, in other three compounds are ionic compounds & they conduct electricity in their molten state.

In the given question, u = – 30 cm and f = -20 cm. so, the object lies between F (20 cm) & C (40 cm). Therefore, a real image is formed beyond C, that is beyond 40 cm. Formula ...

As we know that, the oxygen during photo- synthesis comes from splitting of water molecules into hydrogen and oxygen gas.

You must know that alveoli play a crucial role of respiration. It has a large surface area with very thin walls which is richly supplied with blood vessels.

Copper gets a green coating due to the formation of a mixture of copper carbonate (CuCO₃) and copper hydroxide when it reacts with carbon dioxide gas and the moisture present in air. This is called tarnishing of copper.