Structure of an Atom
Our modern understanding of the atom is based on the atomic theory put forward by the English chemist John Dalton in 1807. Dalton’s idea was that atoms were the basic building blocks of the elements. He thought of them as indivisible particles that could join together to make molecules.
Although certain parts of the theory have had to change as a result of what we have discovered since Dalton’s time, his theory was one of the great leaps of understanding in chemistry. It meant that we could explain many natural processes.
Whereas Dalton only had theories for the existence of atoms, modern techniques (e.g. scanning tunnelling microscopy) can now directly reveal the presence of individual atoms.
Subatomic particles inside an atom
Research since Dalton’s time has shown that atoms are made up of several subatomic particles.
The electron was discovered in 1897, followed soon after by the proton.
Crucial experiments then showed that an atom is mostly space occupied by the negatively charged electrons
Scientist also discovered the positively charged nucleas
it was clear that atoms consisted of three subatomic particles – protons, neutrons and electrons.
How does an atom look
As you can see this whole model is called an atom , The round lines around the nucleas are called electron shells , electrons shells actually do not exist but is a metaphore to describe the electron spin and movement. The nucleas in the middle are made up of proton and neutron , they are sticked togeather due to the strong force. The particles around the nucleas are called electrons. The electrons are held within the atom due to a electrostatic force. This is how an atoms looks like
Properties of Protons , Neutrons and Electrons
Protons and neutrons almost have the same mass , both are a mass of 1 relative charge
Electrons have virtually no mass (1/1840 or 0.00054 of the mass of a proton).
The electrons have 1/1840 mass of a proton cause the protons gets its mass from the strong force while the electrons get there mass from the higgs field
Protons and electrons have equal and opposite charges (+1 and −1, respectively), while neutrons are electrically neutral (have no charge).
Although atoms contain electrically charged particles, the atoms themselves are electrically neutral (they have no overall charge). This must mean that in any atom there are an equal number of protons and electrons. In this way, the total positive charge on the nucleus (due to the protons) is balanced by the total negative charge of the orbiting electrons.
As the charge of electron , proton and neutrons adds up it would be 0 , -1 + 1 + 0 = 0
The simplest atom is the hydrogen atom, which has one proton in its nucleus. It is the only atom that has no neutrons; it consists of one proton and one electron.