Size Of Nuclei

What is meant by size of nucleus? do all nuclei are of same size?

Statement-1: Density of nuclear matter is same for all nuclei Statement-2: Density has nothing to do with mass and size of nucleus.

Constant Rate Production OF Nuclei||Successive Decay OF Nuclei A ->B ->C ->

At a given instant, 60% of the radioactive nuclei in a sample are left undecayed. After 20 s, 85% nuclei have disintegrated , mean life of nuclei

At a given instant, 60% of the radioactive nuclei in a sample are left undecayed. After 20 s, 85% nuclei have disintegrated , mean life of nuclei

The nuclei of which one of the following pairs of nuclei are isotons ?