How do isotopes of the same atom react chemically? How do isotopes of the same atom compare in size?

Atoms of the same elements differing in the number of neutrons in their nuclei are known as isotopes. Thus, isotopes of an element have the same atomic number but different atomic mass number. Isotopes of an element have similar chemical properties but different physical properties.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

the volume increases