The atomic model
In 1932, James Chadwick discovered the Uncharged subatomic particle, with a mass of 1 relative to a proton. 鈥 a particle with no charge in the nucleus of the atom.
The modern model of the atom.
Today, scientists use an atomic model that has a central, positively-charged nucleus that contains:
- positively-charged Subatomic particle with a positive charge and a relative mass of 1.
- neutral neutrons
Negatively-charged electrons orbit the nucleus in shells.
An atom鈥檚 nucleus gives it most of its mass.