What is the structure of an atom?
Atoms can be described in different models, but the most used ones are the Bohr's Model and Schrödinger's Model, both describe the distribution of the internal sub-atomic particles that compose the atom.
The subatomic parts that make the structure of the atom are the following:
- Protons - Positive sub-atomic particle with mass of 1 amu.
- Neutrons - Neutral sub-atomic particle with mass of 1 amu.
- Electrons - Negative sub-atomic particle.
Protons and Neutrons are considered nucleons because they are located inside the nucleus area. Electrons are located outside in an electron cloud.
- Bohr's Model defines that the protons and neutrons are distributed inside the nucleus and the electrons are outside in "rings" with defined positions. It is a simpler model that is today used to teach basic chemistry. This model has one quantum number.
- Schrödinger's Model, or the Quantum Atomic Model, is the most modern and accurate one, in which, on this three-dimensional model, the nucleons occupy an area in the center of the nucleus and the electrons are distributed in "orbitals" in which they can probably be. This model has four different quantum numbers that define the probability to find an electron in a certain region.
How does it influence chemical behavior?
This distribution of electrons on different orbitals can allow, or not, connections called "bonds". When an electron has 8 electrons on its outermost shell, it is a stable atom, meaning that it doesn't make any connections. The Noble Gases are an example of stable atoms/elements.
When an electron has more or less than 8 electrons on its outermost shell, it is an atom that can make bonds, which can be metallic, ionic or covalent. This influences on its behavior when reacting with other elements. Elements with 7 electrons on its outermost shell (valence electrons) react well with atoms that can donate an electron, such as elements that have 1 valence electron.
