How do you know how many electrons are in an atom?

Answer 1

Except for ions, the number of electrons in an atom are equal to the number of protons. The atomic number will tell you the number of protons, and consequently the number of electrons in an electrically neutral atom.

In the case of an ion, adjust the number by the indicated charge; for example Na+1 will have 11 (the atomic number of Na) - 1 (since electrons have a negative charge, you subtract the charge) = 10 electrons.

Answer 2

Atoms are neutral, meaning they have the same number of protons as electrons. The number of protons is called the atomic number (it is the little number on top of an element's symbol on the periodic table). So the atomic number tells us not only the number of protons, but also the number of electrons too (since they are the same amount).

Answer 3

The number of electrons in an atom is equal to the number of protons in its nucleus, which is the atomic number of the element. This information can be found on the Periodic Table. Electrons are negatively charged particles that balance out the positive charge of protons in the nucleus to keep the atom electrically neutral.

Answer 4

the # of electrons and protons is the same as the atomic #