Answer: Most of the stars in the universe are main sequence stars — those converting hydrogen into helium via nuclear fusion. A main sequence star may have a mass between a third to eight times that of the sun and eventually burn through the hydrogen in its core. Over its life, the outward pressure of fusion has balanced against the inward pressure of gravity. Once the fusion stops, gravity takes the lead and compresses the star smaller and tighter.
Temperatures increase with the contraction, eventually reaching levels where helium is able to fuse into carbon. Depending on the mass of the star, the helium burning might be gradual or might begin with an explosive flash.
Answer:
Following are the responses to this question:
Explanation:
They can measure the spontaneity of the reaction with the form,
Substituting the values of 
in the above expression information mostly on the playfulness of the reaction would be given to us from the expression above. This reaction is spontaneous if the price of 
is negative, and if it is positive the response is not random. At equilibrium, the values of 
are 0.
You did not provide possible answers, but one possible might be that the current atomic theory is so sound and plausible that there should not be anything that could change it in the near future.
Answer: Option (C) is the correct answer.
Explanation:
An ion is defined as a specie which is formed when a neutral atoms tends to gain or lose an electron.
When a neutral atom gain an electron then it forms a negative ion whereas when a neutral atom tends to lose an electron then it forms a positive ion.
For example, a neutral fluorine atom on gaining an electron will form 
ion. And, a sodium atom on losing an electron forms 
ion.
When a group of atoms form ions then it tends to form polyatomic ions.
Thus, we can conclude that group of atoms that gains or loses electrons is called a polyatomic ion.
