Most stars spend the majority of their lives converting core hydrogen to what? select all that apply.
a. iron
b. silicon
c. helium
d. carbon e. oxygen f. energy

The correct answer is Option c.

Explanation:

Hydrogen is the main element that is present in most of the stars. The stars undergo nuclear fusion reaction.

Nuclear fusion reactions are the reactions in which two smaller nuclei combines or fuses together to form a single heavier nuclei.

The reactions which undergo in most of the stars are:

The overall equation for the above reactions is:

The product of the reactions is helium nuclei.

Hence, the correct answer is Option c.

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.