The basic units of chemistry are the atom. An atom is a structure in which matter is organized in the physical world or in nature. Its structure is made up of different combinations of three sub particles: neutrons, protons and electrons. Molecules are made up of atoms. This is the smallest part from which an element can be made.
The basic units of Chemistry are Atom.
For example, let’s imagine we have a piece of iron. We split it. We still have two pieces of iron but smaller ones. We start them all over again, again… each time we’ll have more and smaller pieces. There will come a time when we will only have a piece so small that it can no longer be divided.
If we could split it, it would no longer be iron, it would be another element on the periodic table. This very small piece is an iron atom.
definition of atom
We define an atom as the smallest particle into which an element can be divided without losing its chemical properties.
The word is derived from Greek, which means indivisible.
At the time these particles were baptized, it was believed that they could not actually split, although we know today that they are made up of even smaller particles.
Structure and parts of an atom What are the particles of an atom?
The atom is made up of three sub-particles:
Proton, positive charge.
Neutron, without electric charge (or neutral charge).
Electron, negatively charged.
In turn, it is divided into two parts:
hub. Made by neutrons and protons.
crust. Made by electrons only.
The basic units of Chemistry are Atom.
Protons, neutrons and electrons are the subatomic particles that make up the atomic structure. What is different between them is the relationship established between them.
Electrons are the lightest subatomic particles.
The mass of the positively charged proton is about 1,836 times that of the electrons. Neutrons, only without the electric charge, are of the same weight as protons.
Protons and neutrons are grouped together in an atomic nucleus.
That is why they are also called nucleons. Nuclear energy is the energy that holds protons and neutrons together.
Therefore, the atomic nucleus has a positive charge (of protons) in which almost all of its mass is concentrated.
What is Atomic Theory?
Currently, the idea that matter is composed in this way is scientifically well established.
However, throughout history, different theories have been developed about the structure of matter. They are atomic models.
These are the most important nuclear theories and models defined in the history of nuclear energy.
John Dalton’s Atomic Theory.
Thomson’s atomic model.
Ernest Rutherford Model.
Niels Bohr’s atomic model.
The description of electrons orbiting around the nucleus corresponds to the simple Niels Bohr model.
What are the properties and characteristics of an atom?
The basic units of chemistry are atoms.
They are preserved as such, they are not created or destroyed during chemical reactions. They are simply arranged differently by creating different links between them.
What is an atom? Atomic groups combine to form molecules and other types of material.
On the basis of structure, the different chemical elements represented in the periodic table of chemical elements differ.
In the periodic table we can find the atomic number and mass number of each element:
What is atomic number?
It is denoted by the letter Z.
This number indicates the number of protons in the nucleus.
All atoms with the same number of protons belong to the same element and have similar chemical properties.
For example, if they have a single proton it is a hydrogen atom (Z = 1).
What is mass number?
The mass number is denoted by the letter A.
It refers to the sum of protons and neutrons present in the element.
Isotopes are two atoms that have the same number of protons, but different numbers of neutrons.
Isotopes of the same element have chemical and physical properties that are similar to each other.
What are isotopes?
It happens that not all atoms of an element have the same number of neutrons in their nuclei.
This is called an isotope. Isotopes have (nearly) similar chemical properties, but other physical properties.
More than one isotope of practically all elements is known.
Isotopes are very important in the nuclear power industry.
Uranium enrichment is about converting one isotope of uranium into another, more unstable isotope of uranium.
Without these unstable isotopes, the fission chain reaction could not have occurred.
On the other hand, the nucleus has a certain number of electrons around it, which are negatively charged.
The total charge (positive) of the nucleus is equal to the negative charge of the electrons, so the total electric charge is neutral.