What's the problem ? Hardness is not the definition of a metal.
You need to expand your thinking. EVERY element is solid, liquid, and gas, over different ranges of temperature ... including all of the metals. There are only TWO elements that are liquid AT ROOM TEMPERATURE, and mercury is one of them. But on a mild day at the south pole, mercury is solid too.
Answer:
b
Explanation:
orbital overlap electron densities.
Answer:
mining of clay limestone and then heated to a certain temperature of 1450⁰ in a cement kiln