Iron is said to be abundant in nature. About how many percent of the
earth’s crust is iron.
What refer to the casehardening process by which the carbon content of
the steel ear the surface of a part is increased?
The percentage of nitrogen in ammonia is _______________%
Steel is an alloy of iron and carbon with limits on the amount of
carbon to less than _______ percent.
The following statements are true except one which one.
_________ is preferred for horticultural crops and for tobacco and
potatoes.
The special chrome steels of the stainless variety
contain how many percent of chromium.
The brown colour of the pulp obtained from chemical pulping is due to
the present of
Ammonia when used directly as a fertilizer is to be injected about_____
under the surface to keep it from seeping out.
