Atoms and Molecules

Atoms and Molecules | Smallest particle.

Astrophysics.

The solar system model of the atom states-
Atoms consist of a nucleus with a number of electrons in orbits around that nucleus, similar to a solar system

We know now that any matter – solid, liquid, gas – consists of atoms and molecules. But what practically can we get from this knowledge? How useful is this knowledge?

Already by the end of the 19th century this knowledge proved to be useful. At least I would mention 2 things.

First, it’s the understanding of what the heat means, understanding of the law… of the energy conversational law, which opens the way for creating all our heat engines, our automobiles, our airplanes and all the rest that is moving and carrying us from one point to another point.

 Even greater were these consequences for chemistry. 

The understanding that molecules are the elements of any chemical agent, and atoms are those bricks of which those molecules are constructed of, opened the way for plenty of new discoveries in chemistry.

Plenty of new chemical agents were created by chemistry already by the end of the 19th century. And despite the fact that all those advantages and technical progress which were the consequence of this new knowledge, were already evident.

There was one very important question, still open, about 1.5 centuries ago. And the question was really very important. We know that everything consists of atoms.

But what are those atoms?
How are they constructed?

Are they really elementary or do they have some structure? Nobody knew. Another topic – “How do atoms feel about each other?” They do repulse when they are too close or they do attract when they are rather far. 

And there is a point of equilibrium due to the existence of which molecules do exist, and solid bodies and liquids do exist.

But what is the nature of those forces? The question was open. Actually by the end of the 19th century there were two candidates. Only two types of forces were known by this moment to physicists, to researchers.One is a gravitational force which does attract any masses to each other.

Any particle possessing mass is feeling this gravitational attraction. Yes. But if you try to apply the well-known Newton's formula for the force which appears between two bodies having masses at a certain distance, if you try to apply this formula to atoms you will find out that the result is negligibly small.

This force is very weak. It can be sufficient only for big astronomical bodies. We are feeling how the very big Earth is attracting us.




But two very, very small atoms do not feel this gravitational attraction at all. It’s miserable, negligible in comparison, for example, with electromagnetic forces – another interaction well-known to physicists by the end of the 19th century.

But in order to feel electromagnetic forces you need electric charges. And according to what physics and chemistry knew atoms and molecules are electrically neutral. It means that probably they should include charges inside themselves. It means that those charges probably are hidden somewhere inside atoms.

And there inside atoms the distribution of charge over atoms is not even. And due to this fact from the outside, outside the atom looks like electrically neutral. But when you approach it closely you see what it is not absolutely so.