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.