Question

Why do atoms have an overall neutral charge ?

Answer 1

They don't

Answer 2

Well, unless it's an ion

Answer 3

They have the same number of protons and neutrons

Answer 4

and they have same magnitude of charge but opposite signs..

Answer 5

Overall neutral charge as the number of protons (which carries a +1 each) equals number of electrons (which carries a -1 each).

Answer 6

From a sufficient distance, the particles that make up an atom can be seen as a single entity with a charge averaged over the constituent charges of the individual particles. This is similar to how we can treat a complex gravitational n-body system, from far enough away, as a single particle with a point mass equal to the total mass at the centroid.

But, this is a simplification -- let's call it the point-charge simplification of an atom -- and to more fully account for all the intricate behavior of atomic systems, one must consider the charges of individual particles and their respective (probabilistic) positions.

Answer 7

Hi! I'm just going to combine the answers so far.

queelius outlined an important principle, and others identified that the charges are balanced.

There are many charges in an atom. Protons have a +1 charge and electrons have a -1 charge, like dauspex said.

The atom is commonly thought to be organized like this:Uh, that's a rough representation...