The isotope that has 8 protons, 8 neutrons, and 8 electrons is Oxygen-16 (represented as 16O). In this isotope, the number of protons (which defines the element) is 8, corresponding to the element oxygen on the periodic table.
To break this down: protons are positively charged particles found in the nucleus of an atom, while neutrons are neutral particles that also reside in the nucleus. Electrons, which are negatively charged, orbit around the nucleus. For an atom to be neutral, the number of protons must equal the number of electrons; thus, 8 protons and 8 electrons make this oxygen atom electrically neutral.
Oxygen-16 specifically refers to the total number of protons and neutrons in the nucleus (8 protons + 8 neutrons = 16), which gives us its mass number of 16. This is the most abundant and stable isotope of oxygen, making it essential for life on Earth.