Answer:
Protons, neutrons, and electrons are the three main subatomic particles found in an atom.
Explanation:
Answer:
1. 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
Atoms are the smallest form of the substance. examples of atoms are in elemental forms such as copper, helium, silver. Diatomic molecules are made up of identical atoms. Examples are I2.. F2 and Br2. Formula units are those compounds that are made up of two or more elements such as -No2, KMnO4,<span>C3H8, MgCl2, HgBr2, Ba(OH)2</span>