PLEASEHELP WILL MARK BRAINLIEST

Answer:
2. Isotope, one of two or more species of atoms of a chemical element with the same atomic number and position in the periodic table and nearly identical chemical behavior but with different atomic masses and physical properties. Every chemical element has one or more isotopes.
3. Since the vast majority of an atom's mass is found its protons and neutrons, subtracting the number of protons (i.e. the atomic number) from the atomic mass will give you the calculated number of neutrons in the atom. In our example, this is: 14 (atomic mass) – 6 (number of protons) = 8 (number of neutrons).
Explanation: Try rewording the questions when looking it up. Hope this helps
Answer:
9. 2(2n^2)
10. Electron Shell
11.-
12.-
13.-
14.-
Explanation:
i hope it helped