Write a long paragraph about the structure of carbon-12. include the following vocabulary: electron, proton, neutron, orbital, nucleus, isotope, negative, postive.

Explanation:

So many isotopes are present in nature that is the same elements having different structures or atomic weight which makes them different, although having the same name is because of the presence of changed number of neutrons in the nucleus.  

Like in the case of carbon and isotopes that are stable are two in number one is carbon 12 and the other is 13, 12 is the more abundantly found in nature. Proton’s number in the element we have here (i.e carbon) and electron’s number must be same all difference is brought up by neutrons.

answer: c.

explanation:

it's c. elements are placed in rows based on how may valencies electrons have.