Is there a vacuum between molecules?

Question

Is there a vacuum between one molecule of gas in the air and the next be it N2, H2, O2 or whatever else?

Is there a vacuum between molecules of a liquid?

Is there a vacuum between molecules of a solid?

Consider that a liquid is less dense than a solid, and gas is less dense than liquid (like for like).

Answer 1

I would say no because the space between atom nuclei are occupied by the electrons belonging to the atoms that go to make up the molecules.

Molecules are linked by the sharing of electrons, so this explanation would stand for them as well.

The sub-atomic empty space is not a vacuum because the definition of a vacuum is:

2 a : a space absolutely devoid of matter b : a space partially exhausted (as to the highest degree possible) by artificial means (as an air pump) c : a degree of rarefaction below atmospheric pressure

It is not absolutely devoid of matter, because is occupied by the electrons (therfore nothing else can occupy this space: it is already filled), and the second definition are referring to the space between molecules, not the space in the molecules.

Answer 2

Since the question asks about molecules, why have many answers referred to atoms ?

Water (present in the air around us) is made of three atoms bonded together.

So...
I'm no expert...
but...
I believe to make a perfect vacuum, all molecules/atoms need to be removed from a space. So working on this assumption I'd say YES there is only a vacuum between one molecule and the next.
[However, this assumes that there are no sub-atomic particles hanging around (quarks and neutrinos etc)]

In a LIQUID the molecules/atoms are much closer together, and in a SOLID much closer still. The bonds in a liquid are less strong than in a solid, (and in a strong solid, the bonds are extra strong)

Beyond this, I guess the answer somewhat depends on the definition of the word vacuum.

Answer 3

a vacuum is generally defined as being without any atoms so in a sense the space between atoms is a vacuum but really the concept of a vacuum just does not apply here.
There will still be photons/virtual particles and loads of other exotic mass/energy around but none of this stuff is generally included in day to day calculations of pressure so can be safely ignored here.

On the liquid/gas/solid issue life is simple for gases - there is nothing between molecules of the gas so it could sensibly be called a vacuum.
For liquid/solid there are no gaps between molecules, the electrons overlap so there is no between to be concerned about.

Answer 4

Sort of.

If we think of a "classical" vacuum IE like in deep space then yes you are right - although there will be lots of sub atomic particles whizzing around like photons and neutrino's

Also because of quantum mechanics there is a sea of particles being created and then destroyed all the time. This sort of creates a quantum foam between atoms - the overall number of particles is still zero though, but it has been detected, this is zero point energy.

Answer 5

an atom consist of a nuclei and electrons orbiting the nuclei which is at the centre. between the electrons and nuclei is most empty space(vacuum). for example if the a nuclei is taken to be a football in the centre of a football field, the first electron orbit will be roughly the distance of two football fields away (ie massive empty space between them)

Answer 6

No
A true vacuum presents a problem in the form that nature abhors a vacuum and will try to fill the void.

You could expect this vacuum to try to equalise by sucking in the subatomic matter surrounding it, I tend to think it is not possible for such a vacuum to exist in the subatomic world.
The area is surrounded by continuously smaller subatomic matter.
If there is a vacuum how are you going to measure it; with a subatomic pressure meter?
It is easy to say yes there is a vacuum but much harder to prove it.

Answer 7

Yep. Essentially an atom is surrounded by nothing but empty space, in which the electron is located.

Answer 8

yes

Answer 9

Yes. Atoms are made up of mostly nothing.

Answer 10

Eureka!