Question

Define the structure of an atom?(chemistry 9th class)

Answer 1

atom is made up of three particles in these are called subatomic particles first is proton second is neutron and third is electron the proton and neutron on the present in the centre of the cell which is called nucleus and the electrons revolving around the nucleus



Answer by cp

Answer 2

structure of atom according to class 9th.....

atom is made up of three fundamental particles called electrons , protons and neutrons.......

electron was discovered by JJ Thomson
Proton was discovered by Goldstein
neutron was discovered by chadwick

many scientist performed experiments and give theories about the structure of atoms....

1. John Dalton :- he said that the structure of atom is something like a watermelon or Palam pulling where the electrons were scattered anywhere and the rest space was positive charge......

2. Ernest Rutherford :- he performed an experiment where used gold foil which was only 10,000 atoms thick and fired the Ray of Alpha particles made by Helium atoms from radium atom and observed that most of the Alpha particles past the gold foil very easily and in a straight line but some Alpha particles went by small angle and there was only one Alpha particle among 12000 which came back at the angle of 180 degree. on the basis of this observation Rutherford said that there is a strong positive charge located at the centre of atom which he called please where protons and neutrons for embedded
drawbacks of Rutherford Model :-
Rutherford could not explain the movement of electrons that in which part does electrons move around the nucleus...

3. Neil Bohr's model of atom :- Bohr's model of atom was a very successful modal because he showed the movement of electrons around the nucleus and said that electrons revolve around the nucleus in well defined orbitals called energy cells ( k,l,m,n)