Physics
Answer
Matter is made up of very small particles called molecules and a molecule is the smallest unit of matter which can exist independently and retains all its physical and chemical properties. It is made up of various elements. An element is a substance which cannot be subdivided into two or more simpler substances by any means. Atoms are the smallest unit of an element which may or may not exist independently.
Related Questions
Compare the characteristics of solids and liquids.
Describe a simple activity to show that molecules have spaces between them.
Harsh's mother asked him to close the knob of the gas stove after use, but he forgot. After some time, his mother observed a smell of rotten cabbages in the whole house. She went to the kitchen and saw that the knob was still open. She closed it immediately. Later, she made Harsh understand that it is very dangerous to keep the knob of the stove open, as it can catch fire.
(a) Which characteristic of gas is responsible for this smell in the whole house?
(b) Name the gases that a gas cylinder usually contains.
(c) Is it possible to keep solids and liquids compressed in a cylinder?
(d) What precautions should we follow to avoid any mishaps in the kitchen?
(e) What would you do in such a situation?
Why can't liquids be compressed?