What is an isotope? Explain why isotopes having different number of neutrons are still considered to be the same element on the periodic table.

Isotopes of any given factor all incorporate the equal variety of protons, so they have the identical atomic wide variety (for example, the atomic wide variety of helium is usually 2). Isotopes of a given factor include exceptional numbers of neutrons, therefore, special isotopes have special mass numbers.

atoms of the same element with different mass are called isotopes. Atoms of the same element with same number of proton but different number of neutrons.

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be