Answer:
The inner planets, Mercury, Venus, Earth and Mars, are the closest terrestrial planets to the sun. They are mostly made up of iron, silicon, magnesium, sulfur, aluminum, calcium and nickel. So, that means that they are solid.
NOTE: In your answer you put that the inner planets are made up of gas. That is wrong. The Outer Planets are made up of gas, thats why they are known as the Gas Giants.
Hope this helps :)
