Ernest Rutherford New Zealand physicist, 1909
The Nuclear Model
“Nucleus”
According to this theory an atom consists of positively charged particles concentrated at the center known as the nucleus. The main idea is that an atom has electrons surrounding a nucleus that contains protons and neutrons. Most of the space inside an atom is free this is because the size of the nucleus is very small as compared to the size of the atom. Also, the electrons revolve around the nucleus in well-defined orbits.
Atom Structure
Rutherford proposed that atoms have a very small, dense core at their center, which he called the nucleus. This nucleus contains most of the atom’s mass and is positively charged.
Electron orbits
Surrounding this nucleus, electrons orbit at a relatively large distance compared to the size of the nucleus. This model depicted the atom as having a central nucleus with electrons moving around it, somewhat like planets orbiting the Sun.
Positive charge
The positive charge of the nucleus balances the negative charge of the electrons, keeping the atom electrically neutral. The nucleus’s positive charge attracts the negatively charged electrons, which helps keep them in orbit around the nucleus.
Space in atoms
Rutherford’s model showed that atoms are mostly empty space. The nucleus is very tiny compared to the overall size of the atom, which explains why atoms are mostly empty space.