Question

Which shows the correct order of processes leading up to the formation of a main sequence star?

a. Gases condense to form a nebula, gravity causes the nebula to collapse and spin, nuclear fusion occurs, and a protostar forms.
b. A protostar forms, nuclear fusion occurs, gases condense to form a nebula, and gravity causes the nebula to collapse and spin.
c. Gases condense to form a nebula, gravity causes the nebula to collapse and spin, a protostar forms, and nuclear fusion occurs.
d. A protostar forms, gases condense to form a nebula, gravity causes the nebula to collapse and spin, and nuclear fusion occurs.

Answer 1

C. Should be the answer it worked for me

Answer 2

Answer: Option c

Explanation:

Nebula is a birthplace or stellar nursery where stars take birth. Gases condense to form a nebula. Then these gases start to collapse under their own gravity. This heats up the matter which is condensing which gives rise to a protostar. After the formation of protostar, if the mass is sufficient and temperature is high enough, nuclear fusion reaction kicks in at the core and starts to release energy and enters the main sequence.

Hence, the correct order of process leading up to the formation of main sequence star is: option c

1. Gases condense to form a nebula
2. gravity causes the nebula to collapse and spin
3. a protostar forms
4. nuclear fusion occurs.