White vitriol is

Which of the following metals is inert towards reaction with $H_2O$?

$CO_2$ is passed through lime water. Initially,the solution turns milky and then becomes clear upon continued bubbling of $CO_2$. The clear solution is due to the formation of:

Which colour is developed in the solution when alkaline earth metals are dissolved in liquid ammonia?

State whether the following statements are True or False:
$(1)$ Plaster of Paris is used to join fractured bones and keep them immobilized.
$(2)$ Calcium carbonate and soil are the raw materials for cement production.

Fill in the blanks:
$(1)$ Cement is also known as......
$(2)$ Cement was first introduced by......