The planets are divided into two groups name them

The inner and outer planets.

In our Solar System, astronomers often divide the planets into two groups — the inner planets and the outer planets. The inner planets are closer to the Sun and are smaller and rockier. The outer planets are further away, larger and made up mostly of gas.

Iwould you figure it out but you don't have a picture or in your question as to what the physical property you're looking for is