Question

passage
stars are responsible for creating all the elements heavier than hydrogen and helium, which were formed during the big bang. the process of creating these elements is called stellar nucleosynthesis, and it occurs through nuclear fusion reactions within stars. these reactions happen when the immense pressure and heat in a stars core force atomic nuclei to combine, releasing energy and forming heavier elements.
the first stars in the universe were formed from clouds of gas and dust that collapsed under their own gravity. as these clouds collapsed, they became denser and hotter, eventually reaching temperatures high enough for nuclear fusion to begin. the fusion process started with hydrogen, the simplest element, combining to form helium.
as stars age, they continue to fuse heavier elements, progressing through a series of fusing stages. after hydrogen is exhausted, helium begins to fuse, creating carbon and oxygen. this process continues, with heavier elements being formed as the stars core becomes older, hotter and denser.
this pressure from heat and fusion pushes outward ensuring the star does not collapse in on itself.
in the snapshot below, the star is stable because gravity is balanced by the gas and radiative pressure.
check - in questions
stellar nucleosynthesis is when elements are created through ____________ in a star
what is the force holding gasses together?
why does gravity not cause everything to collapse in?

Explanation:

Stellar nucleosynthesis occurs via nuclear fusion in stars. Gravity is the force that holds gases together in star - formation. In a stable star, the inward pull of gravity is balanced by the outward pressure from gas and radiation, preventing collapse.

Answer:

1. nuclear fusion
2. gravity
3. The outward pressure from gas and radiation balances the inward pull of gravity.