What is the atom?
You are seeing this page.
So we know there are you and computer in the space.
"You" and "the computer" are objects.
The objects can be counted as 1 or 2 or more.
If you are broken or you drop computer on the floor, the objects are to lose as to the property of the object.
However, the character of what was you, or the thing which constitutes the fragment of a computer has not changed.
What constitutes such objects is called "substance."
The atom is true character of substance.
Atom is composed of electrons present in the nucleus and its outskirts in the middle.
Nucleus is constituted of "Proton" and "Neutron".
Proton has a positive charge, and neutron has no charge. (1
H has no neutron.)
Types of atoms is determined by the number of protons in the nucleus.
Hydrogen is composed by only one electron and one proton.
Helium is composed of two protons and two electrons.
<- Model of the hydrogen atom. Nuclei and electrons are gravitated.
There is a gray ring on the atomic model.
This is referred to as electron shells, it is like a house of electron.
And an electron orbit is in an electron shell. It is like a room of electron.
Electron shell has a name K shell, L shell, M shell from that shell closest to the nucleus.
Electron go into from the electron shell closer to the nucleus. K shell is empty, the electron enters the K shell on a priority basis.
The atom will be stable when shell is filled by electrons.
Then the atom is electrically neutral.
The electron up to 2 to enters K shell. The electron up to 8 to enters L shell. The electron up to 18 to enters M shell.
If electron shell is full, electron enters of the outer electron shell.
The outermost electron shell determine the property of the atom.
If you arrange it well, you can make the table. The similar atoms of the property is lined up to the table.
"Periodic table" was born in this idea.
Next, we will describe the periodic table.