why are there the same # of protons as there are electrons?

Answer 1

Protons carry a positive electric charge. Electrons carry a negative electric charge. The magnitude of the charge carried on both the, positive, protons and the, negative, electrons are equal....meaning that the total electric charge on an object is zero only if the number of protons exactly equals the number of electrons.

In an atom, for example, the net electric charge is zero and there are equal numbers of protons and electrons. When an atom has an unequal number of protons and electrons (in the case when the atom is oxidized or reduced...loosing electrons or gaining electrons), the atom becomes an ion and has a net charge.

If something does have an unequal balance between protons and electrons and has a net charge, it will be attracted/repelled to other objects with a net charge as well. Like charges repel and dissimilar charges attract, so all the + charges will attract all the - charges and vice-versa, eventually forming overall neutral objects.

Answer 2

An individual atom is neutral if it has the same number of electrons as protons. If an atom gains or loses one or more electrons, it is no longer called atom, but is an ion.

In terms of the universe, that is an excellent question. Every theory of the origin and development of the universe makes a prediction about the relative numbers of particles. If that prediction doesn't match our observations reasonably well, then there may be a problem with the theory. I don't know how accurately the actual ratio is known. See the second reference for the possible implications of a local imbalance. Even if it's true, it wouldn't apply on a large scale.

Answer 3

A proton or electron is very concentrated electric charge, expressed as coulombs /kg. An ordinary-sized object like a coin, contains octillions of both. If you were to remove just a few electrons from, say a dime, it would acquire a very strong positive charge that would pull them back. So the number of protons and electrons in an object is almost exactly equal.

Answer 4

Because by nature the atom has to have a charge of 0. Having the same number of electrons and protons makes this possible.

Answer 5

Charge is a conserved quantity and electrons and protons are the only stable charged particles, so an equal number today implies that the net charge of the universe at the time of the Big Bang was zero. There is no current explanation for the initial conditions of the universe, but there is a strong predisposition amongst cosmologists to assume they are as simply as observation lets you assume them to be. Zero is simple.

That said, given the above, I *can* tell you there is no vast region of space with a significant net charge. If there were, it would create a vast electric field diverging outward/inward from it and repel/attract electrons until there was no significant net charge.