WHAT ARE ATOMS?
Atoms are fundamental building units of the matter, invisible by eye. All the matter, including water, oxygen, metals, even our body, is made of atoms.
Term ‘atom’ comes from the Greek word ”Atom” or ”Atomos” which means indivisible.
However, atom is divisible. It is made of three (3) subatomic particles. Protons, electrons and neutrons.
Protons have a positive charge, electrons have a negative charge, and neutrons don’t have a charge, so they are neutral.
Atom in its natural state is neutral, balanced. It has equal amount of positive and negative charge. So, it has the same number of protons and electrons.
In which way these three (3) subatomic particles build an atom?
Protons and neutrons are holding together and they are making a nucleus. Nucleus is the core, the center of the atom. Around the nucleus, we have an electron’s cloud, and inside that cloud, there are electrons and they are circling around the nucleus. They have their orbits in which they are moving.
For an example we will take a Lithium atom. It has three (3) protons, three (3) electrons and three (3) neutrons. This is how we are going to mark them:
We can see that electrons are around the nucleus, actually, they are ”flying” around the nucleus. We can make a conclusion that atom is something that is very alive. Something is happening here, some energy.
Altough here, protons, electrons and neutrons are all shown to be the same size (because of more easy way to display it), in reality, things are different.
Radius of an electron’s cloud is ten thousand (10 000) times bigger than nucleus. Protons and neutrons have equally the same mass. In comparison to them, electrons are very tiny. More than 1800 (almost 2000) times, electrons are smaller than protons (or neutrons). Proton is little bit smaller than neutron. (Protons are around the 99,86% the same mass as neutrons.) The biggest part of an atom is actually an empty space without mass.
Atoms are making chemical elements. Total there is 118 chemical elements. Chemical elements are perfectly ordered in the Periodic system of elements. (Periodic table)
What is the difference between atoms of two elements? For example, what is the difference between atoms of hydrogen, lithium and copper? The difference is in the number of protons. Hydrogen has 1 proton, lithium has 3 protons, and copper has 29 protons. Logically, if all of this elements each one has a different number of protons, that also means that they all have a different number of electrons and neutrons.
In a balanced state, the number of protons and electrons is the same. Number of neutrons is also the same as number of protons and electrons. If we add one more proton to an atom, we will get a new element, because, lets remember, elements are differentiating by the number of protons that they have. If we add a neutron to an atom, then we have an isotope, in other words, the heavier version of that atom. So, it is still the same element.
And if an atom lose or gets electron, that is called an ion.
Pictures are actually only tools that are helping us in the visualization. We should not take them completely as trustworthy display of an atom.