Does number of protons always equal to number of electrons?

2 Answers
Mar 24, 2018

Not necessarily

Explanation:

Number of protons always equal number of electron, but that's the case with a neutral atom.

A neutral atom is an atom of any element that has no electric charge over it.
This implies that it has same number of protons and electrons in it.
It means it has same amount of positive and negative charge, which cancel each other, and the atom as a whole becomes electrically neutral.

But in case an atom tends to form an ionic Bond with any other atom, it either loses or gains electron(the number of electrons lost or gained depends on the number of electrons present in the valence shell of the atom) and becomes ionized. In this case, the number of electron and proton differ.

Thus, in an ionized atom or simply an ion, the number of protons and electrons are not the same but in a neutral atom they are.

Mar 24, 2018

No.

Explanation:

Protons have a positive charge, and electrons have a negative charge. If there is an equal amount of electrons and protons, they will cancel each other out giving the atom an overall neutral charge.

In the structure of an atom, protons are clumped up with neutrons (which have a neutral charge) in the centre of the atom, making the nucleus. Electrons surround the nucleus in layers called shells.

There is always two electrons in the first shell (the innermost one). The remaining electrons are split among the next shells. There is not always an evenly split amount of electrons in the shells (excluding the first shell).

There can be two circumstances which fit under this: the outermost shell has fewer electrons than the others, or the outermost shell has more electrons than the others.

In the case of the former, the atom will "donate" however many of its electrons to another atom. The donating atom will then become a cation. The cation has fewer electrons than protons. That means that some of the protons will not be cancelled out, giving the atom an overall positive charge.

In the case of the outermost shell having lesser electrons than the rest, it will accept however many electrons from another atom. This accepting atom will then become an anion. The anion has more electrons than protons. This means that some of the electrons will not be cancelled out, giving the atom an overall negative charge.

Note: I'm not sure, but I think only one electron is accepted or donated.