In a Voltaic cell,what is the positive electrode (cathode) made of?

What type of oxide is phosphorus pentoxide $(P_4O_{10})$?

Which gas is produced when a base reacts with a metal?

Name two metals which react with dilute $HNO_{3}$ to evolve $H_{2}$ gas.

An aluminium can was used to store ferrous sulphate solution. It is observed that in a few days,holes appeared in the can. Explain the observation and write the chemical equation to support your answer.

An element $A$ is soft and can be cut with a knife. It is very reactive to air and cannot be kept open in air. It reacts vigorously with water. Identify the element from the following: