Question

using the periodic table and your knowledge of atomic structure. compare the number of electrons in a carbon-12 and carbon-14 isotope.
a both have 6 electrons.
b carbon-12 has 6 electrons and carbon-14 has 8 electrons.
c carbon-12 has no electrons and carbon-14 has 2 electrons.
d carbon-12 has 12 electrons and carbon-14 has 14 electrons.

Explanation:

Isotopes of an element have the same atomic number (number of protons), and in a neutral atom, the number of electrons equals the number of protons. Carbon - 12 and Carbon - 14 are isotopes of carbon, so they have the same atomic number (6 protons). Thus, in neutral atoms, both have 6 electrons. Option B is wrong as it says Carbon - 14 has 8 electrons, option C is wrong as carbon atoms have electrons, option D is wrong as the number of electrons is based on atomic number (6) not mass number (12 or 14).

Answer:

A. Both have 6 electrons.