Write the definitions of isotopes, isobar and isotone.
Write the unit of mass and its definition.
A nucleus of mass number $189$ splits into two nuclei having mass number $125$ and $64$ . The ratio of radius of two daughter nuclei respectively is:
The particles which can be added to the nucleus of an atom without changing its chemical properties are called
The increasing order of atomic radii of the following Group $13$ elements is
As compared $^{12}C$ atom, $^{14}C$ atom has