Bohr Model of an atom
Bohr suggested that –
• Electrons spin around the nucleus in an individualized separate path or unattached orbit.
• The electrons do not emit any energy while moving Indies special orbits.
• These orbits are also called as Energy Levels.
• They are represented using letters or numbers as shown in the figure below –
The Neutrons
J. Chadwick discovered that there is another sub-atomic particle present in the atom. This particle carries no charge and is known as a Neutron. Therefore, we can conclude that atom consists of three types of particles –
Electrons |
which carry a negative charge |
Protons |
which carry a positive charge |
Neutrons |
they are neutral |
The distribution of electrons in different shells or orbits
• If Orbit number = n
• Then number of electrons present in an Orbit = 2n2
• So, for n =1
• Maximum electrons present in shell – K = 2 * (1)2 = 2
• The outermost shell can contain at most 8 electrons.
• The shells in an atom are filled in sequence.
• Thus, until the inner shells of an atom are filled completely the outer shells cannot contain any electrons.