The document discusses the structure of atoms, including early models proposed by Thomson, Rutherford, and Bohr. It introduces subatomic particles like electrons, protons, and neutrons that make up atoms. Experiments showed atoms are divisible and composed of these charged and uncharged particles. Atoms have an internal structure consisting of electrons orbiting around a nucleus made of protons and neutrons.

1. CH 4 Structure of an Atom

2. INTRODUCTION
• Thomson’s model of an Atom
• Rutherford’s model of an Atom
• Bohr’s model of an Atom
• Neutrons
• How are electrons distributed in different orbits
• Valency
• Atomic number and Atomic mass
• Atomic number
• Atomic mass
• Isotopes
• Isobars
• Intext Questions
• Exercise Questions

3. Existence of charged particles in Atom
• An electrically charged objects can attract the uncharged of objects
(by inducing opposite charged in them)
• Comb acquires electric charge and in the second case, glass rod
acquires electric charged
• Where does this is electric charge come from ?
• As comb, Glass Road etc. constitute matter and matter is made up of
atoms, there must be some Charged particles present in the matter
and hence in the atom.
• In other words, atom is divisible

4. Existence of charged particle in atom
• Further experiments were
performed which showed that
Atom is not the smallest particle
but is made up of still smaller
particles called sub atomic
particles.
• The three main subatomic particles
were electronn, protons and
neutrons.
• In other words, an atom has an
internal structure of its own