Isotopes of an element share the same number of protons but have different numbers of neutrons. Let's use carbon as an example. There are three isotopes of carbon found in nature – carbon-12, carbon-13, and carbon-14. All three have six protons, but their neutron numbers - 6, 7, and 8, respectively - all differ.
Of course they are, why wouldn't they? Carbon 12 is the isotope found the most in earth's surface. Carbon 13 takes up about 1.1 percent of the earth's surface.
The answer should be (4) they are negative subatomic particles and are found surrounding the nucleus. The nucleus is formed by neutrons and protons. Neutrons are neutral and protons are positive.
