9. The mass of the Sun is 1.99x 1090 kg, and the radius of the Earth's orbit around the Sun is 1.5x1011 m From this, calculate the orbital speed of the Earth

The orbital period of Titan ... Hyperion, another moon of Saturn, orbits at a mean radius of 1.48 x109 m. ... mass of the Sun is 1.99x1030 kg. ... calculate Pluto's orbital period in Earth days.

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.