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Nuclear Chemistry. Lesson 1: Islands of Stability. 63. 197. Cu. Au. 29. 79. Nuclear Chemistry – Bell work. The isotope notation for an atom of copper and an atom of gold are given below: How could you change a copper atom into a gold atom?
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Nuclear Chemistry Lesson 1: Islands of Stability
63 197 Cu Au 29 79 Nuclear Chemistry – Bell work • The isotope notation for an atom of copper and an atom of gold are given below: • How could you change a copper atom into a gold atom? • What would you need to change? Give specific numbers. • Why is this change called a nuclear reaction?
The Big Question • What is the range of the number of neutrons found in isotopes of various elements? • Goal- Determine how many neutrons are required to make a stable element with a given number of protons.
Island of stability • Plot this isotope • # of protons? • # of neutrons? protons = neutrons Band of stability
Notes • Nuclear chemistrystudy of atom nucleus • Band of stabilityrange in neutron # for given proton # for naturally occurring isotopes
Stable isotope? • Inside gray area? Stable isotope • On edge? Radioactive • Outside? Isotope not stable Not an element • What is an element? • Isotope detected? • Element 118 discovery last fall • Lasted 0.05 milliseconds
p = 12 • n = 12 • p = 92 • n = 60 • p = 118 • n = 77 • p = 35 • n = 55 • p = 92 • n = 146 • p = 77 • n = 114
p = 12 • n = 12 • p = 60 • n = 92 • p = 77 • n =118 • p = 35 • n = 55 • p = 92 • n = 146 • p = 77 • n = 114
Worksheet • Imagine a chemist was trying to create an atom with 60 protons and a mass number of 155. Would this be possible? Why or why not? • Where on the graph would you expect the other isotopes of magnesium to be located (magnesium-25 and magnesium-26)? Explain.
Worksheet • If an element had 90 protons, how many neutrons would be a good number for it to have in order to be considered a stable element? What element would this be? • What do you suppose that little island of gray on the graph represents?
Check-In • Use your graph to determine how many neutrons you would need to make a stable element with 75 protons. • How many neutrons would make a radioactive element with 75 protons?
Answer to #10 • No Yes Yes No Yes
Notes • Radioactiveelements lose pieces of the nucleus over time. • Atoms that exist for a long time are called stable. • Radioactive atoms disappear over time and are called unstable. • Any isotope that lasts long enough to be detected and measured qualifies as an element • Element 118 discovery last fall • 0.05 milliseconds