The correct option is
A A→3,B→4,C→1,D→2,E→6,F→7,G→51. Rutherford did the scattering experiment and observed that some of the rays bounce back. He concluded that there is a mass in which positive charge is concentrated. This marks the discovery of nucleus.
2. J.J Thomson discovered electrons by conducting cathode ray experiment.
3. Dalton postulated that matter is made up of small particles caled atoms
4. Neils bohr postulated that electrons revolve around the nucleus in fixed orbits.
5. James Chadwick discovered neutrons which has no charge.
6. E Goldstein discovered protons by conducting canal rays experiment.
7. Moseley did x ray experiment and concluded that the chemical properties are a periodic function of their atomic number.