Question

why do some natural resources have to be processed?

Answer 1

Some natural resources have to be processed because they cannot be used in their raw state. In raw state they can harm us or be wasted.
For example:food in raw state can harm us

Answer 2

Some natural resources like iron ore have to be processed so that we can get the pure and useful substance from that.Coals are processed to get the substances like coke, coal tar, coal gas which are pure and useful.