Question

How does a nebula become a star?

Answer 1

Hint: In order to answer the given question, we need to know all the facts about the nebula and the stars. Also, we need to know the criteria that are required for the formation of stars. After that we can finally write the answer for the given question.

Complete answer:
First of all, let us find the nebula.
We define nebula as a giant cloud made of dust and gases in space. These gases are helium, hydrogen and other ionized gases. When more than one nebula combines together, we say it as nebulae.
Now, let us find the stars.
We define stars as the huge celestial bodies that are made up of helium and hydrogen which produce heat and light. Stars consist of luminous spheroids of plasma which are held together due to their own gravity.
With time, the nebula becomes so big that under its own gravity it collapses and causes the material to heat up at the centre of the cloud. Thus, the core becomes hot and the formation of stars takes place.

Note: The time taken for a nebula to become a star depends on the size of the star. For example, for a star to be of the size of the sun, it takes about $10000000$ years for the formation. The formation of stars takes place from the accumulation of gas and dust particles that collapses due to their own gravity. It may take millions of years for the formation of a star.