The metal that is usually extracted from sea water is

The metal used to recover copper from a solution of copper sulphate is

Safety fuse wire used in domestic electrical appliances is made of metal of low

The instrument which uses sound waves to measure the depth of oceans is

The best conductor of heat among the following is

What is colour of light related to?

The maximum number of electrons on a principal shell is–

The floral part that receives pollen - grains during pollination is