Ernie(13) asks -“What is at the centre of a black hole? What would happen if you fell into one?”

black-holes

We obviously know something about gravity. We know that it is a force that is generated by the mass of an object. The bigger the mass the bigger the force that it exerts on other objects. So we feel the force of Earth’s gravity on us and the Earth feels the force of the  Sun’s gravity on it. The Sun’s gravitational force keeps the Earth on an orbit around it. If it didn’t exist the Earth and all the other planets would start wandering in space.

Black holes are thought to be a source of a massive gravitational force, because of their mass , which is constantly increasing, and they don’t just pull other matter to them they pull light in as well …thus a black hole. No light – darkness.

So to your question.  I think you could now answer that yourself.

Apply asked “If the pressure on the surface of a gas is increased. What will happen to the inter particle force?

A fascinating question. I asked my friends to look at this and they came up with a couple of definitions which might dictate the way I try to answer this question.
intermolecular

Your question seems to be directed at intermolecular forces between similar particles/molecules 

In a past question I talked about the way water molecules are attracted to each other by things called ‘hydrogen bonds’. This aids the formation of liquid water at very high temperature and low pressures. The molecules ‘like’ being close together. Another molecule is that of carbon dioxide – these are not attracted to each other so strongly. To attract each other they need to be ‘pushed’ much closer together, only then will they form a liquid. For some molecules like butane you need really high pushes because the attraction between the molecules is so small. For some other molecules there is no force of attraction, this can almost be described as repulsion. The gases, Helium, Nitrogen and Hydrogen  are only liquefied under immense pressure (push) and low temperature (low temperature slow the individual molecules down) conditions.