Atomic Models: How to Understand Atomic Models

The study that encompasses all discoveries and calculations relating to atoms and their peculiar behavior is in atomic models.

What is an atom?

The atom is the unit of matter that has a central nucleus of positive electrical charge, surrounded by a cloud of negatively charged electrons.

The nucleus of the atom is made up of neutrons and protons. These electrons are attached to the nucleus by electromagnetic force.

See also: Oblique throw and Hooke's Law.

What are atomic models?

Atomic models are the characteristics of atoms studied by scientists to understand their composition and behavior.

Scientist John Dalton, in the year 1808, presented an explanation of the property of matter. It was the first atomic theory, the basis for the atomic model known today.

You atomic models already showed its first signs of research, in antiquity. The Democritus thinkers (460 a. C) and Leucippus (500 a. C) had the idea that there would be a limit to the small space of the particles.

Thinkers said that they were so small that they would not be able to divide. And this little particle was called an atom. The word comes from the Greek together, which means what cannot be divided.

Dalton model

You atomic models he had one more contribution in his studies with the chemist John Dalton. He created the Dalton Model, also known as the billiard ball model. Its principles are:

• Every substance is made up of small particles called atoms.
• Atoms have different properties, but all atoms in the same element are the same.
• When they form chemical components, atoms do not change.
• Atoms are permanent and do not divide. They cannot be created or destroyed.
• The rearrangement of atoms is chemical reactions.

Thomson model

Physicist Joseph John Tomson was the first to accomplish the feat of splitting atoms. This happened when he was studying about cathode rays.

Between the atomic models, which Thomson discovered was called plum pudding. He showed that rays could be seen as a beam of particles charged with negative electrical energy.

Thomson suggested in 1887 that electrons were a constituent of matter at the universal level. He presented what would be the first ideas related to the internal structure of atoms.

He demonstrated that atoms were made up of uniformly distributed positive and negative electrical charges.

So he created the theory of the electrical nature of matter. He noted that the relationship between charge and electron mass was the same in any gas used in his research. With these feats, in 1897, Thomson became the father of the electron.

Rutherford model

In the year 1911, the physicist Ernest Rutherfor, carried out an experiment to create more among the atomic models that were arising.

Inside a metal chamber, he placed a very thin gold leaf. In this study, he found that some particles were completely blocked and others did not change at all.

The majority, surpassed the leaves but suffering deviations. This was due to the electrical repulsion forces existing between the particles.

According to his studies, he stated that the atom was nucleated and its positive part was in an extremely small volume, which would be the nucleus.

Rutherford's atomic model, or also known as the planetary model, works like a miniature planetary system: electrons move in circular orbits around the nucleus.

The Rutherford-Bohr atomic model

The physicist Niels Henrick David Bohr, perfected the atomic model of Rutherford that came to be called the atomic model of Bohr or the atomic model of Rutherford – Bohr.

In his studies, Bohr established that:

• The electrons that revolve around the nucleus do not do this by chance but have certain orbits.
• Even though it is very small, most of the atom has empty space. The diameter of the nucleus of the atom [and a hundred thousand times better than the whole atom. The fact is, atoms spin so fast they take up all of space.

When electricity passes through the atom, the electron jumps to the next major orbit, returning from one orbit to another.

Understanding Atomic Models

Solving Exercises on Atomic Models