Astronomers observe a region of space where a nebula has changed into a protostar.
How did the density of the material change during this stage?
It increased as nuclear fusion joined the nuclei in the gas together.
It decreased as the material heated up and expanded outwards.
It stayed constant because the total mass of material did not change.
It increased as gravitational attraction caused the cloud to collapse.
84 exam-style questions on AQA GCSE Physics 8.1 Solar system; stability of orbital motions; satellites, covering 8.1.1 Our solar system, 8.1.2 The life cycle of a star, and 8.1.3 Orbital motion, natural and artificial satellites. Each one has a worked solution and a mark scheme showing where the marks go.