If atoms are mostly empty, why things are firm to the touch and in appearance?

Chemist John Dalton proposed the theory that all matter and objects are made up of particles — atoms, and this theory is still accepted by the scientific community, after two hundred years. Each of these atoms consists of an extremely small nucleus and even smaller electrons at a relatively great distance from the city center. If you imagine the table, which is a billion times more atoms would be the size of watermelons. But even then - in the centre is still too small to be seen, not to mention the electrons. Why, then, our fingers do not pass through the atoms? Why the light does not penetrate through these cracks?

To understand this, we need to consider electrons. Unfortunately, in school we were taught simplified concepts — electrons do not actually revolve around the center of the atom like planets around the sun. Though told us so. Instead, the electrons can be represented in the form of a swarm of bees or flock of birds, some movement which is too fast to catch, but you can still see the General shape of this swarm.

the"Dance" of electrons

In fact, the electrons dance, and no word better to describe this process. But this is not a random dance — rather, ballroom dance in which the electrons move in a specific pattern, following the steps established by the mathematical equation named Erwin schrödinger.

These diagrams, the models may differ — some slow and gentle, like a waltz, others fast and energetic, like Boogie. Each electron maintains the same schema, but can sometimes switch to another, if no other electron even this scheme fails to execute. No two electrons in an atom can't move the same way: this rule is called the principle of prohibition Pauli principle.

Although electrons never get tired, switching to a more fast step requires energy. And when the electron moves on a slow circuit, it loses energy. Therefore, when energy in the form of light falls on the electron, it can absorb some energy and move to faster, high "the dance". A ray of light passes across your Desk, because the electrons all atoms trying to capture a little energy from light.

After a while they lose resulting energy, sometimes in the same light. Changes in the nature of absorption and reflection of light gives us the reflection and the colours so we see the table as a solid object.

Resistance to the touch

Why is the table hard to the touch? You may have heard that this is due to the repulsion two negatively charged object would repel each other. But it's not. It is also hard because of the dancing electrons.

If you touch a table the electrons from the atoms in your fingers are close to the electrons in the atoms of the table. And when electrons in one atom closer to the nucleus in the other, their dance is changing. Because the electron is in low energy condition near the single core can't do the same thing next to another — this place is already taken. Newcomers have to move to unoccupied position. Excess energy and need somewhere to put it, not in the form of light this time, but in the form of force from your finger touch.

Therefore, the process of summing up close of atoms requires energy, because all the electrons must move in the other, unoccupied, higher energy state. An attempt to combine all the atoms of the table and thumb together will require a tremendous amount of power — more than your muscles. You feel the resistance of the finger, and the table feels the hardness of your body when touched.