12 electrons. Remember, electrons and protons must be balanced in charge; neutron number may vary.
Tantalum has 73 protons and electrons and its isotopes have 108 or 107 neutrons.
Calcium has 20 protons and electrons and a variable number of neutrons, depending on the isotope.
Thorium 232 has 90 electrons and protons, also 142 neutrons.
Iron has 26 electrons; the number of neutrons is different for each isotope (number of neutrons = mass number - 26).
Francium has 87 protons and electrons; the number of neutrons is different for each isotope and francium has ca. 40 isotopes ad isomers. Number of neutrons = Atomic mass of the isotope - 87
An atomic nucleus contain protons, neutrons and electrons - not oxygen.
Beryllium has 4 protons and normally 4 neutrons in its nucleus. It usually has 4 electrons orbiting that nucleus, but this number can change depending on its level of ionisation.
11 protons and 10 electrons
There are 19 known isotopes of americium, with neutron counts ranging from 136 to 154. Americium-241, the easiest to produce, has 146 neutrons. Number of neutrons = Atomic weight (rounded) of an americium isotope - 95 Each isotope has a different number of neutrons. Americium has also 95 protons and electrons.
The Atomic Number tells us the position of the element in the Periodic Table. It also tells us the number of protons and electrons in an atom of that element. The Atomic Mass/Weight is different. The Atomic Mass is the total numbers of nucleons ( protons and neutrons) in the nucleus of an atom. For a given element the atomic mass can vary. This is because the nucleus may have a different number of neutrons. These different masses of a given element are named 'Isotopes'.
The chlorine atom has 17 protons and electrons.
25 electrons.... ( as the number is 25 : being 25 protons and 25 electrons)