Describe and evaluate the advantages and disadvantages of different fuel sources. [6 marks]

The Mark Scheme:  Fossil fuels are non-renewable/release pollutants/contribute to acid rain Fossil fuels are readily available/low fuel costs/easily transported  Nuclear fuels are non-renewable/produce radioactive waste/health risks due to exposure Nuclear fuels release no carbon dioxide or sulphur dioxide emissions/conserves fossil fuels/cheap to run. Biomass is renewable/does not increase surface carbon levels.  Biomass still releases carbon dioxide

Explain how passive solar heating can be used to heat a greenhouse. [6 marks]

The Mark Scheme: The sun is very hot Visible light/short wavelength infrared energy directly from the sun Transmitted through glass (transparent) Absorbed by walls, floors and furniture in the room. At night the walls, floors and furniture re-emit the energy as infrared with longer wavelengths as they are not as hot. This radiation is not transmitted but reflected back into the room.

What evidence exists to support the Theory that an Asteroid Impact was responsible for the extinction of the dinosaurs? [6 marks]

The Mark Scheme: any 6 from below: KT boundary: below this boundary there are fossils and above this boundary there are none [1] Rare metal element Iridium which is only usually found in meteorites/asteroids is found in the KT boundary [1] Shocked Quartz (in the KT boundary) shows a huge impact must have occurred with a large force [1] Shocked Quartz and Iridium is not spread evenly but is thicker in the South east suggested an impact occurred here [1] Yucatan Peninsula has horseshoe features that match the crater predicted and also there is shocked quartz and iridium found here [1] Crater found on the Yucatan Peninsula – same size as was predicted [1] Cenotes (large circular holes with underground lakes) in Yucatan Peninsula – these are found along fault lines but there are no known fault lines here so they must have formed from an impact [1] Patterns of Cenotes match the shape of the crater found on the Yucatan Peninsula [1] Can’t be coincidence that a large impact occurred and then suddenly the dinosaurs were gone – the impact must have caused the extinction [1]

How is the evolution of our own star the Sun different from stars which are much larger? What will happen to the Sun when it runs out of fuel? [6 marks]

The Mark Scheme: any 6 from below: When our own star, the Sun, runs out of fuel it will go on to form a red giant [1] More massive stars will go on to form red super giants [1] The Sun will emit it’s outer layers as a planetary nebula [1] and then be left as a white dwarf [1] which will cool to form a black dwarf [1]. A more massive star will erupt as a supernova [1] and then either form a neutron star [1] or a black hole [1].

Describe how the moon was formed. [6 marks]

The Mark Scheme: Earth and a second smaller planet (Thea) collided. The force of the collision was enough to nearly destroy both planets. The iron of both planets was dense and became concentrated into Earth’s core. The less dense rocks orbited Earth in an accretion disc. These rocks clumped together to form the Moon. The evidence is that there is no iron on the moon and that it contains the same oxygen compositions as Earth.

Explain the evidence that exists for the Big Bang. [6 marks]

The Mark Scheme: universe is finite in size as shown by the finite numbers of stars. light from galaxies shows red shift correct explanation of red-shift those galaxies moving away fastest/further away show the most red shift the remnants of the Big Bang can be shown as the Cosmic Microwave Background Radiation statement relating to the volume of supporting evidence and agreement from scientists in both theoretic and experimental work.