Answer:
Gaseous; liquid.
Step-by-step explanation:
A planet can be defined as a large celestial body having sufficient mass to allow for self-gravity and make it assume a nearly circular shape (hydrostatic equilibrium), revolves in an orbit around the Sun in the solar system and has a cleared neighborhood.
Some examples of the planet are Mars, Venus, Earth, Mercury, Neptune, Jupiter, Saturn, Uranus, Pluto, etc.
Basically, the planets are divided into two (2) main categories and these includes;
I. Inner planets: these planets are the closest to the sun and comprises of mercury, venus, earth and mars.
II. Outer planets: these planets are beyond the asteroid belt and comprises of jupiter, saturn, uranus and neptune, from left to right of the solar system.
These outer planets are made mostly of gases (hydrogen and helium) causing them to be less dense than the solid inner planets. These gases are generally known to be less dense in terms of physical properties.
In conclusion, Planets in the solar system can vary from rocky and terrestrial objects to gaseous and liquid object.
However, the set of characteristics which is unique to the outer planets are gaseous and liquid.