Nuclear Chemistry and Radioactivity CHAPTER 20 Nuclear Chemistry and Radioactivity 20.1 Nuclear Equations

So far, we have only looked at reactions involving the outer electrons neutrons protons electrons So far, we have only looked at reactions involving the outer electrons

neutrons protons electrons Chemical reactions rearrange elements into new compounds, leaving the elements unchanged Chemical equations

Nuclear reactions create new elements from other elements electrons protons neutrons Chemical reactions rearrange elements into new compounds, leaving the elements unchanged Nuclear reactions create new elements from other elements Nuclear equations Chemical equations

Representing nuclei In nuclear equations we need to keep track of the number of neutrons and the number of protons protons neutrons

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 element symbol

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

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

Like in a chemical equation, a nuclear equation must be balanced Mass number balance (protons + neutrons) 238 = 234 + 4 1) There must be mass number balance 2) There must be charge conservation Charge balance (protons) 92 = 90 + 2

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