Which solvent from the following is used in order to avoid the creation of waste and the pollution of air?

Fill in the blanks:
$(1)$ $.......$ is made using fly ash and slag from the steel industry.
$(2)$ Biogas is used in the production of $.......$ and its byproduct is used as $.......$.

The ozone layer forms naturally by

Among the following, the one which is not a "green house gas" is:

The greenhouse effect is responsible for global warming. Which gases are responsible for the greenhouse effect?

The metal ion responsible for the Minamata disease is