CHAPTER 20 Nuclear Chemistry and Radioactivity 20 1

CHAPTER 20 Nuclear Chemistry and Radioactivity 20. 1 Nuclear Equations

neutrons electrons protons So far, we have only looked at reactions involving the outer electrons 2 20. 1 Nuclear Equations

neutrons electrons protons Chemical reactions rearrange elements into new compounds, leaving the elements unchanged Chemical equations 3 20. 1 Nuclear Equations

neutrons electrons Chemical reactions Nuclear reactions rearrange elements into new compounds, leaving the elements unchanged create new elements from other elements Chemical equations 4 protons Nuclear equations 20. 1 Nuclear Equations

Representing nuclei In nuclear equations we need to keep track of the number of neutrons and the number of protons 5 neutrons protons 20. 1 Nuclear Equations

Representing nuclei In nuclear equations we need to keep track of the number of neutrons and the number of protons 2 protons + 2 neutrons 2 protons 6 element symbol 20. 1 Nuclear Equations

In a nuclear reaction, uranium-238 into thorium-234 and helium-4 disintegrates. The periodic table gives you the number of protons 7 20. 1 Nuclear Equations

Like in a chemical equation, a nuclear equation must be balanced 1) There must be mass number balance 8 Mass number balance (protons + neutrons) 238 = 234 + 4 20. 1 Nuclear Equations

Like in a chemical equation, a nuclear equation must be balanced 1) There must be mass number balance 2) There must be charge conservation 9 Mass number balance (protons + neutrons) 238 = 234 + 2 Charge balance (protons) 92 = 90 20. 1 Nuclear Equations

Nuclear reactions create new elements from other elements In a nuclear equation, there must be: 1) mass number balance 2) charge conservation 10 neutrons protons 20. 1 Nuclear Equations