<h2>Answer: The nucleus becomes entirely helium.</h2>
To shine, the stars transform their hydrogen into helium by means of <u>nuclear fusion</u>. When at half of its life a star is without hydrogen, the nucleus becomes entirely helium and <u>the star declines, becoming colder and brighter due to the energy generated by the nuclear reactions, then the star begins to contract.
</u>
Nevertheless, if the star is bigger, this helium will be also consumed and the nucleus transformed in Carbon, then in Oxigen, and so on. Being the last transformation Iron until the star delivers all its energy.
Note this process will depend on how massive the star is.
Answer:
heat reaches to us from the sun through radiation since there is no medium in space, radiation is the major wat heat travels in space.
A girl leans against a wall and the wall pushes on the girl.
A baseball hits a glove and the glove pushes on the ball.
A cat rubs up against a tree and the tree pushes against the cat
Explanation:
By the statement, Efficiency of a machine is 60% it is meant that 'The work output is 60% of the work input'. If you apply 100J of energy for a machine, it will be able to life load of 60 J only
