Thank you for reporting, we will resolve it shortly
Q.
$ _{19}{{K}^{40}} $ and $ {{\,}_{20}}C{{a}^{40}} $ are known as
VMMC MedicalVMMC Medical 2007
Solution:
Isotopes: They are atoms of same element which have same atomic numbers but different atomic masses, eg, $ _{\text{1}}^{\text{1}}\text{H,}_{\text{1}}^{\text{2}}\text{H} $ and $ _{\text{1}}^{\text{3}}\text{H}\text{.} $ Isobars: They are atoms of different elements which have different atomic numbers but similar atomic masses. Isotones: These are atoms of different elements which have same number of neutrons. Their atomic numbers and atomic masses both are different, eg, $ _{6}^{12}C $ and $ _{\text{7}}^{\text{15}}\text{N}\text{.} $ $ _{\text{19}}^{\text{49}}\text{K} $ and $ _{\text{20}}^{\text{49}}\text{Ca} $ are isobars because they have same atomic mass (40).