Iron is said to be abundant in nature. About how many percent of the
earth’s crust is iron.
What field of study encompasses procurement and production of metals.
The brown colour of the pulp obtained from chemical pulping is due to
the present of
Which of the following potassium fertilizers are more useful for
horticultural crops tobacco and potatatoes.
What refer by the ability of steel to be hardened
through to its centre in large section?
The liquor is screened to exclude ________ material
