Isobars
The atoms of different elements having same mass numbers but different atomic numbers, are called isobars.
e. g., 1 H 3, 2 He 3 and 10 Na 22, 10 Ne 22 are isobars.
Isotones
The atoms of different elements having different atomic numbers and different mass numbers but having same number of neutrons, are called isotones.
e. g., 1 H 3, 2 He 4 and 6 C 14, 8 O 16 are isobars.
Isomers
Atoms having the same mass number and the same atomic number but different radioactive properties are called isomers,
Nuclear Force
The force acting inside the nucleus or acting between nucleons is called nuclear force. Nuclear forces are the strongest forces in nature.
� It is a very short range attractive force.
� It is non-central. non-conservative force.
� It is neither gravitational nor electrostatic force.
� It is independent of charge.
�
It is 100 times that of electrostatic force and 10 38 times that of gravitational force.
According to the Yukawa, the nuclear force acts between the nucleon due to continuous exchange of meson particles.
Mass Defect