SPH3U Group: Rishi Sharma Pashv Shah Roy Wang Eric Li

Summary How it works  Theory, physics concepts Founders of the field Sociological impact Environmental impact Practical application  electricity

Nuclear Energy Nuclear energy is released by the splitting or merging together of the nuclei of atom

Theory Nuclear power is energy released from controlled nuclear reactions Two types of reactions: – Nuclear Fission – Nuclear Fusion

Nuclear Fission Types: Spontaneous and Induced Transmutation: The resultants are not of the same element as the atom

Nuclear Fission Spontaneous Fission: Radioactive decay that occurs naturally in heavy isotopes - Alpha particles are used to split the nuclei -Occurs over time very slowly Alpha particle: a particle that consists of 2 protons and 2 neutrons ( positive charge)

Nuclear Fission Induced Fission: When a neutronis used to split a nucleus, releasing immense, efficient energy -Doesn’t occur naturally, we do it!

Nuclear Fission Theory Naturally: By smashing the alpha particles at the nucleus: – It will split the nucleus (positive), converting some of its mass to energy – Doesn’t work! – The alpha particles repel most of the time (both the particles and the nucleus are positive) – Reactions only occur a small amount of the time This is alpha radiation

Nuclear Fission Theory We do this: Smash a neutron (no charge), into the nucleus: – Causes a bond and SPLIT! – Releases energy, and a few more neutrons All of those neutrons do the same thing! – Causing a chain reaction All energy released ( heat and) gamma radiation Gamma radiation: radiation made of photons (measure of light)

E= mc 2 Energy mass Velocity of light, squared

How do you use it? The products of the fission (+ the new neutrons) reaction weigh less than the initial atom Einstein: Energy and matter are different forms of the same thing; can be converted back and forth The difference: initial mass-new mass This can be used to solve for Energy in E= mc 2

What is the nucleus made of? It has to be HEAVY, therefore unstable (allows an easy split!) Most likely Uranium or Plutonium Plutonium is made from bombardment of Uranium Perfect Mixture: U-235 – Isotope of uranium, decays naturally – One extra neutron, SPLIT! Example : – 1 0 n U Ba Kr n

Diagram

Fission Summary

Nuclear Fusion When similar atomic nuclei are bonded to created a heavier nucleus Mass of object plays role in absorption or release of chemicals simplest case: two protons have to be close enough for their repulsion to be overcome by the nuclear force More powerful than fission  create a heavier nucleus instead of a lighter one Used in the Sun, Nuclear warheads Not practical for Nuclear Power!

How it all started… Ernest Rutherford split the first atom –1917 His team bombarded nitrogen with alpha particles – one proton had more energy than a alpha particle 1932 – 2 students of Rutherford tried to split a atom using a particle accelerator The bombarded lithium with protons - 2 helium James Chadwick discovered neutron in 1932 Nuclear fission achieved in Rome

How it all started… was proven that uranium nucleus was split into roughly 2 equal parts Later noticed that if fission reactions released additional neutrons, a chain could be created Led to the first man made reactor- Chicago Pile-1, later became a part of Manhattan project

Manhattan Project Einstein  deeply interested in nuclear fission for weaponry Wrote a letter to US President: – Einstein was on the verge of something, other countries could harness the power as well – US government funded “Manhattan Project” (classified) – Researched and developed first atomic bomb

Practical Use Electricity Nuclear makes 15 % of the world’s electricity Atomic Bombs, Nuclear Warheads

Creating Energy Example If you were to take 1 Hydrogen Atom, it weighs in at 1.67 × 10^(-27) kg In reality if you were to use 1 kg of water you would have.111 kg of Hydrogen atoms E= mc^2 E= (.111)(300,000,000)(300,000,000) = 10,000,000,000,000,000 Joules

In the Power Plant…

Nuclear Jeopardy

Questions?