Multiple choice

Unlike the inner planets, which are all formed of rock, the outer planets are composed of 

  1. Lava

  2. Rock

  3. Gases

  4. Water

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The inner planets (Mercury, Venus, Earth, Mars) are terrestrial and rocky. The outer planets (Jupiter, Saturn, Uranus, Neptune) are gas giants composed primarily of hydrogen, helium, and other gases.