2. Artificial Transmutation Mr. ShieldsRegents Chemistry U02 L04

3. Induced (or artificial) Transformation … The process of striking nuclei with high energy particles in order to create (I.e change them into) new elements AN ALCHEMISTS DREAM ! Converting Lead into Gold

4. Early History 42He + 147N  178O + 11p 1919 Rutherford performs the first induced transformation in a laboratory in a laboratory Slams an alpha particle into a nitrogen nucleus and creates oxygen! Remember this reaction? It’s how Rutherford discovered the Proton +

5. Early History This New Zealand stamp recognizes the world's first successful alchemist who converted nitrogen atoms into oxygen atoms.

6. Induced vs. Natural -INDUCED TRANSMUTATION is not the same as Natural Radioactivity (or NATURAL TRANSMUTATION) Radioactivity (or NATURAL TRANSMUTATION) -In Natural Transmutation a nucleus spontaneously decays into another nucleus by emitting one of several particles into another nucleus by emitting one of several particles - INDUCED TRANSMUTATIONS require one particle to be slammed into another to induce the change slammed into another to induce the change

7. Atom Smashers - Induced transformations reactions require hi velocity particles to overcome the repulsion of the charged particle particles to overcome the repulsion of the charged particle or nucleus or nucleus - These Transmutations were originally achieved in LINEAR Accelerators like the one at Stanford (SLAC) Accelerators like the one at Stanford (SLAC) The first type of Accelerator built Lower range of collision energies achieved P+Nuc+ 2 miles long

8. Atom Smashers CIRCULAR Accelerators like the one at FERMI Lab are typically used in ATOM Smashing - Used to explore what is inside neutrons and protons - Energies greatly exceed Linear accelerators - High energy electrostatic & magnetic fields accelerate CHARGED particles which then slams into the target CHARGED particles which then slams into the target - Particles typically approach the speed of light - Particles typically approach the speed of light

9. Fermilab in Illinois stretches almost 10 square miles. The Tevatron is the world’s highest energy atom smasher Fermi Lab Booster ring Worlds largest Hi energy particle Collider (built in 1983) Can produce Particle Energies Of 2 trillion EV 4 miles in circumference

10. Transuranium elements Since Rutherford, Scientists have made hundreds of new isotopes AND new elements - All elements above atomic no. 92 are called TRANSURANIUM ELEMENTS TRANSURANIUM ELEMENTS - All transuranium elements are MAN MADE in atom smashers using induced transmutation smashers using induced transmutation 1.- 1940: First element above atomic no. 92 are made 238 92 U + 1 0 n ——> 239 92 U + gamma ray beta 239 92 U ——> 239 93 Np (2.36 days) 238 92 U + 1 0 n ——> 239 92 U + gamma ray beta 239 92 U ——> 239 93 Np (2.36 days)

11. Transuranium elements - 1950: Elements through atomic no. 98 (Cf; Californium) 242 96 Cm + 4 2 He ——> 245 98 Cf (45 min) + 1 0 n - 1960: Elements through atomic no. 102 (No: Nobelium) 248 96 Cm + 12 6 C ——> 256 102 No (3.3 sec) + 4 1 0 n - -1998: Highest atomic number synthesized to date is Atomic Number 118 (As yet unnamed)

12. Problems: Write the nuclear equation for the bombardment of Calcium – 40 with a positron, forcing the emission of an alpha particle as one of the products. Write the nuclear equation for the bombardment of Calcium – 40 with a positron, forcing the emission of an alpha particle as one of the products. 40 Ca + 0 e  36 K + 4 He 20 +1 19 2 So we can use nuclear eqs. To determine what radio- Isotope should be created if we know the other Particles. Try this …