Explanation:
Atomic radii is measured using the distance between nucleus of 2 atoms rather than the distance between the nucleus and outermost shell because:
- There is no clear/sharp boundary of the orbital. This is why it is called an electron cloud.
- Also, the exact location of the electron is not known. What is known is the probability of finding the electron there.
Due to this, it is not possible to measure the atomic radii precisely. That's why the distance between the nucleus of two atoms is used.
