1. P2.6.2 Nuclear fusion P2 Physics P2.6.2 Nuclear fusion P2 Physics Mr D Powell

2. Mr Powell 2012 Index Connection Connect your learning to the content of the lesson Share the process by which the learning will actually take place Explore the outcomes of the learning, emphasising why this will be beneficial for the learner Connection Connect your learning to the content of the lesson Share the process by which the learning will actually take place Explore the outcomes of the learning, emphasising why this will be beneficial for the learner Demonstration Use formative feedback – Assessment for Learning Vary the groupings within the classroom for the purpose of learning – individual; pair; group/team; friendship; teacher selected; single sex; mixed sex Offer different ways for the students to demonstrate their understanding Allow the students to “show off” their learning Demonstration Use formative feedback – Assessment for Learning Vary the groupings within the classroom for the purpose of learning – individual; pair; group/team; friendship; teacher selected; single sex; mixed sex Offer different ways for the students to demonstrate their understanding Allow the students to “show off” their learning Activation Construct problem-solving challenges for the students Use a multi-sensory approach – VAK Promote a language of learning to enable the students to talk about their progress or obstacles to it Learning as an active process, so the students aren’t passive receptors Activation Construct problem-solving challenges for the students Use a multi-sensory approach – VAK Promote a language of learning to enable the students to talk about their progress or obstacles to it Learning as an active process, so the students aren’t passive receptors Consolidation Structure active reflection on the lesson content and the process of learning Seek transfer between “subjects” Review the learning from this lesson and preview the learning for the next Promote ways in which the students will remember A “news broadcast” approach to learning Consolidation Structure active reflection on the lesson content and the process of learning Seek transfer between “subjects” Review the learning from this lesson and preview the learning for the next Promote ways in which the students will remember A “news broadcast” approach to learning

4. Mr Powell 2012 Index P2.6.2 Nuclear Fusion a)Nuclear fusion is the joining of two atomic nuclei to form a larger one. b)Nuclear fusion is the process by which energy is released in stars. c)Stars form when enough dust and gas from space is pulled together by gravitational attraction. Smaller masses may also form and be attracted by a larger mass to become planets. d)During the ‘main sequence’ period of its life cycle a star is stable because the forces within it are balanced. e)A star goes through a life cycle. This life cycle is determined by the size of the star. f)Fusion processes in stars produce all of the naturally occurring elements. These elements may be distributed throughout the Universe by the explosion of a massive star (supernova) at the end of its life. a)Nuclear fusion is the joining of two atomic nuclei to form a larger one. b)Nuclear fusion is the process by which energy is released in stars. c)Stars form when enough dust and gas from space is pulled together by gravitational attraction. Smaller masses may also form and be attracted by a larger mass to become planets. d)During the ‘main sequence’ period of its life cycle a star is stable because the forces within it are balanced. e)A star goes through a life cycle. This life cycle is determined by the size of the star. f)Fusion processes in stars produce all of the naturally occurring elements. These elements may be distributed throughout the Universe by the explosion of a massive star (supernova) at the end of its life.

5. Mr Powell 2012 Index What energy source should we use????

6. Mr Powell 2012 Index a) Nuclear fusion is the joining of two atomic nuclei to form a larger one.

7. Mr Powell 2012 Index b) Nuclear fusion is the joining of two atomic nuclei to form a larger one. Nuclear fusion involves two atomic nuclei joining to make a large nucleus. Energy is released when this happens. The Sun and other stars use nuclear fusion to release energy. The sequence of nuclear fusion reactions in a star is complex, but overall hydrogen nuclei join to form helium nuclei. Here is one nuclear fusion reaction that takes place: hydrogen- 1 nuclei fuse with hydrogen-2 nuclei to make helium-3 nuclei; ENERGY

8. Mr Powell 2012 Index b) Nuclear fusion is the process by which energy is released in stars..... Or on Earth... “Tokamak” - toroidal chamber with magnetic coils Here is a simple version of a Tokamak. A Tokamak is simply a fusion reactor. The hot plasma is the yellow donut in the middle. It is created by a large current of electricity. Red & Green rings provide a magnetic field to contain and shape the plasma. Without the containment you could have a nasty accident.

9. Mr Powell 2012 Index Tokamak - toroidal chamber with magnetic coils http://www.splung.com/

10. Mr Powell 2012 Index Summary Questions Fusion Fusion the process by which energy is released when atoms merge together When small atoms come together under a lot of temperature and pressure This happens in main sequence stars which are “on fire” or “fusing” constantly combining hydrogen isotopes to form helium or larger elements.

11. Mr Powell 2012 Index Multichoice Quick Questions...

12. Mr Powell 2012 Index

13. Mr Powell 2012 Index e) A star goes through a life cycle. This life cycle is determined by the size of the star.

14. Mr Powell 2012 Index e) A star goes through a life cycle. This life cycle is determined by the size of the star.

15. Mr Powell 2012 Index Nebula... 1.A nebula is a collection of gas and dust between many stars. 2.The dust is pulled together by gravity. 3.It collapses further and forms a protostar. 4.Pressure increases due to increased density. 5.Atoms collide more often so temperature increases.

16. Mr Powell 2012 Index Protostar... 1.As the gas nebula collapses, a protostar is formed. 2.Nuclear fusion begins and the star becomes a main sequence star.

17. Mr Powell 2012 Index d) During the ‘main sequence’ period of its life cycle a star is stable because the forces within it are balanced. 1.This is the longest stage of the star’s life. 2.The star is stable as long as there is enough hydrogen left. 3.Energy is generated in the core where H atoms fuse to form He. 4.Energy radiating away from the star balances the pull of gravity.

18. Mr Powell 2012 Index Red Giant “sizes” 1.Most Hydrogen has been used up. The core is now mostly He. 2.The core contracts under the force of the star’s gravity. 3.This makes the core much hotter. He nuclei fuse to form C, N and O. 4.Outer layers expand up to 100 times in size. 5.Outside is cooler so looks red. – A red giant. 6.Our Sun will form a red giant in about 4bn years

19. Mr Powell 2012 Index White Dwarf 1.When all the He has been used up, the star becomes a white dwarf, which cools gradually 2.This is Sirius A. 3.The small white spot bottom left is Sirius B, a white dwarf

20. Mr Powell 2012 Index White Dwarf 1.There is a white dwarf at the centre of the cloud of dust in this cocoon nebula. 2.The dust is matter thrown out from the outer layers of the red giant which collapsed to form the white dwarf.

21. Mr Powell 2012 Index When it cools the white dwarf forms a black dwarf or may explode to form a supernova Black dwarf Supernova f) Fusion processes in stars produce all of the naturally occurring elements. These elements may be distributed throughout the Universe by the explosion of a massive star (supernova) at the end of its life.

22. Mr Powell 2012 Index 1.When the core is mostly iron, it collapses very quickly, becomes very dense and heats up to billions of degrees C. 2.The atoms split up into neutrons. The outer layers are pulled in by gravity and it explodes in a Supernova. 3.The whole process lasts only about 2 weeks. 4. The core is now left as a neutron star, or if the original star was big enough, a black hole. Supernova II...

23. Mr Powell 2012 Index Red - Supergiants 1.Stars bigger than our Sun form red supergiants. 2.Like red giants, they run out of Hydrogen. 3.Helium in the core fuses to make C, N and O. 4.When He runs out, the core collapses again. 5.Temperature increases and energy is produced by more fusion to make elements up to iron. 6.Fusion to make bigger elements would require energy to be supplied so is not possible.

24. Mr Powell 2012 Index Betelgeuse is a red supergiant in Orion….

25. Mr Powell 2012 Index The arrow shows the position of betelgeuse You can easily see Orion on a clear night. Look for the 3 stars in a straight line which make up the hunter’s belt Betelgeuse.....

26. Mr Powell 2012 Index Life Cycle Summary...

27. Life Cycle of a Star....

28. Mr Powell 2012 Index e) A star goes through a life cycle. This life cycle is determined by the size of the star.