From what materials are the following made up of ?

(a) Test tube rack

(b) Test tube holder

(c) Measuring cylinder

(d) Wire gauze

(e) Mortar and pestle

Mention one use of each of the following equipments:

(a) Spirit lamp

(b) Test tube

(c) Conical flask

(d) Evaporating dish

(e) Wire gauze

(f) Beaker

(g) Mortar and pestle

(h) Measuring cylinder

(i) Glass tube

(j) Gas jar

(k) Reagent bottle

Answer the following questions in brief:

(a) Why is chemistry known as an experimental science?

(b) Why are most of the apparatus made of glass?

List any five precautions to be taken while performing an experiment in a chemistry laboratory.