gravityhere is a more detailed answer
Put simply, there is not just empty area between particles. The particles
themselves actually are not just particles -- they actually spread/smear out
-- and there are many other things that can make an appearance beside
protons, electrons, and neutrons. For more details, read on.
With really small spaces, smaller than atoms, the common view of hard, solid
"particles" turns out not to work too well. Scientists have learned that
particles are not quite like the 'hard spheres' you might imagine. In fact
particles in many ways are more like 'smears' that spread over lots of
locations all at once. I tell you this because an atom is not like a solar
system -- atoms are not like planets revolving around a star. An atom is
more like a bunch of overlapping smears, whose positions are not exact (think
of a water color painting instead of a pixels on a screen). What that means
is that there is not really 'empty space' inside an atom.
Actually, there is a baseline of energy everywhere in space, often described
as 'soup' from which particles are constantly emerging and disappearing
(maybe think of fishes diving out of water and landing back in). So there
are not only the particles of the atom, but lots of other ones around too,
all overlapping to some degree.
Also, different scientists might answer this question differently, because
fundamentally, scientists are still trying to figure out what is 'space' and
what is not 'space'. Some people think of space as nothingness, but modern
scientists realize there is a lot going on everywhere -- it is anything but
empty. Some people describe space as a scaffold a sorts -- a canvas for the
painting known as the universe, which can be a good way to think of it.
Others say space is the universe's gravitational field -- although I think
that is too limited a view. Right now science still has not figured out how
gravity works, so no matter what, the concept of 'space' is still very much
a mystery.
Other questions we do not know... Is a 'small' bit of space the same as large
tracts of space? That is also a subject of debate. Scientists are still
trying to figure out, for instance, if there is a 'smallest' possible amount
of space that cannot be subdivided (some scientists think there is). Another
question is how many dimensions are there in space? Most people think of
three spatial dimensions (and time being a fourth), but some scientists
describe other dimensions that people cannot observe (yet). There are reasons
for proposing additional dimensions, but the math is really complicated.
The point is this: we are still trying to figure out just what space is like
(from big universe-sized spaces to tiny spaces inside atoms), what things
are in there, and how they all interact. Like so much of science, there is a
lot more for us to figure out.
hope it helps me