The life cycle of a star begins with a large cloud of dust and gas which collapses. Five later stages of the life cycle of a very massive star are: black hole protostar red supergiant stable star supernova Place these stages in Table 9.1 in the order in which they occur. [Table 9.1]

1. (a)Place these stages in Table 9.1 in the order in which they occur.[2]
2. (b)(i)The original collapse of the cloud of dust and gas that formed the Sun was caused by an inward force. State the name of the inward force.[1]
3. (b)(ii)Further collapse is prevented by an outward force. The Sun will remain in the stable stage of its life cycle for a few billion years. Describe what causes the outward force.[1]
4. (c)(i)One of the first supernovas ever observed is known as SN185. It was formed from the explosion of a star in the Milky Way galaxy. The remnants of SN185 are at a distance of 8200 light-years from Earth. State what is meant by a 'light-year'.[1]
5. (c)(ii)State the time that passed between the explosion that formed SN185 and the electromagnetic radiation from the explosion reaching Earth.[1]
6. (c)(iii)A recently observed supernova is SN2014J. The remnants of SN2014J are 12 million light-years from Earth, outside the Milky Way. There is no redshift seen in the electromagnetic radiation from the remnants of SN185 but a large redshift is seen in the electromagnetic radiation from the remnants of SN2014J. Explain this difference.[2]
7. (d)Most of the atoms found in the early Universe were hydrogen and helium. The Universe now contains atoms of heavier elements. Explain how the heavier elements are formed.[2]