Kanya has a material X whose molecules are separated by large distances or spaces. Nidhi has a material Y which takes the shape of its container. Gagan has a material Z which has no definite volume. Which of the three materials is/are in gaseous state ?
A hard material X which is mined from the earth is used as a household fuel and also for the generation of electricity at Thermal Power Stations. A soft material Y is also used as a fuel in the form of candles. A gaseous material Z which occurs along with petroleum is increasingly being used as a fuel in running vehicles in its compressed form.
(a) What are the materials, X, Y and Z?
(b) When materials X, Y and Z are burned separately:
(i) Which material burns by producing a yellow, luminous flame?
(ii) Which material ultimately burns without producing a flame?
(iii) Which material can burn in a gas stove by producing a blue flame?