1. Nuclear Intro

2. Nuclear Reactions vs. Normal Chemical Changes
Nuclear reactions involve the nucleus
The nucleus opens, and protons and neutrons are rearranged
The opening of the nucleus releases a tremendous amount of energy that holds the nucleus together – called binding energy
“Normal” Chemical Reactions involve electrons, not protons and neutrons

3. The Nucleus
Remember that the nucleus is comprised of the two nucleons, protons and neutrons.
The number of protons is the atomic number.
The number of protons and neutrons together is effectively the mass of the atom.

4. Isotopes
Not all atoms of the same element have the same mass due to different numbers of neutrons in those atoms.
There are three naturally occurring isotopes of uranium:
Uranium-234
Uranium-235*
Uranium-238

6. Isotopes
Two Categories
Unstable – isotopes that continuously and spontaneously break down/decay in other lower atomic weight isotopes
Stable – isotopes that do not naturally decay but can exist in natural materials in differing proportions

7. Radioactivity
It is not uncommon for some isotopes of an element to be unstable, or radioactive.
We refer to these as radioisotopes.
There are several ways radioisotopes can decay and give off energy known as radiation.

9. Types of Radioactive Decay Alpha Decay
Loss of an -particle (a helium nucleus) He 4 2 U
238 92
 Th
234 90 He 4 2 +

10. Types of Radioactive Decay Beta Decay
Loss of a -particle (a high energy electron)  −1 e or I
131 53 Xe 54
 + e −1

11. Types of Radioactive Decay Gamma Emission
Loss of a -ray (high-energy radiation that almost always accompanies the loss of a nuclear particle) 

12. Penetrating Ability

13. e He γ e helium atom without any electrons
Radioactive Particle
Nuclear Symbol
Pertinent Information
alpha
beta
gamma
positron 4 He 2
helium atom without any electrons e -1
high energy electron, no mass with a negative charge γ
high energy ray with no mass and no atomic number e +1
mass of an electron but a positive charge

14. Nuclear Reactions
Alpha emission
Note that mass number goes down by 4 and atomic number goes down by 2.
Nucleons (nuclear particles… protons and neutrons) are rearranged but conserved

15. Nuclear Reactions Beta emission
Note that mass number is unchanged and atomic number goes up by 1.

16. Write Nuclear Equations!
Write the nuclear equation for the alpha decay of radon-222
222Rn  218Po He
Write the nuclear equation for the beta emitter Co-60.
60Co  60Ni e 86 84 2 -1 27 28

17. Nuclear Reactions vs. Normal Chemical Changes
Nuclear reactions involve the nucleus
The nucleus opens, and protons and neutrons are rearranged
The opening of the nucleus releases a tremendous amount of energy that holds the nucleus together – called binding energy
“Normal” Chemical Reactions involve electrons, not protons and neutrons

18. The Nucleus
Remember that the nucleus is comprised of the two nucleons, protons and neutrons.
The number of protons is the atomic number.
The number of protons and neutrons together is effectively the mass of the atom.

19. Isotopes
Not all atoms of the same element have the same mass due to different numbers of neutrons in those atoms.
There are three naturally occurring isotopes of uranium:
Uranium-234
Uranium-235*
Uranium-238

21. Isotopes
Two Categories
Unstable – isotopes that continuously and spontaneously break down/decay in other lower atomic weight isotopes
Stable – isotopes that do not naturally decay but can exist in natural materials in differing proportions

22. Radioactivity
It is not uncommon for some isotopes of an element to be unstable, or radioactive.
We refer to these as radioisotopes.
There are several ways radioisotopes can decay and give off energy known as radiation.

24. Types of Radioactive Decay Alpha Decay
Loss of an -particle (a helium nucleus) He 4 2 U
238 92
 Th
234 90 He 4 2 +

25. Types of Radioactive Decay Beta Decay
Loss of a -particle (a high energy electron)  −1 e or I
131 53 Xe 54
 + e −1

26. Types of Radioactive Decay Gamma Emission
Loss of a -ray (high-energy radiation that almost always accompanies the loss of a nuclear particle) 

27. Penetrating Ability

28. e He γ e helium atom without any electrons
Radioactive Particle
Nuclear Symbol
Pertinent Information
alpha
beta
gamma
positron 4 He 2
helium atom without any electrons e -1
high energy electron, no mass with a negative charge γ
high energy ray with no mass and no atomic number e +1
mass of an electron but a positive charge

29. Nuclear Reactions
Alpha emission
Note that mass number goes down by 4 and atomic number goes down by 2.
Nucleons (nuclear particles… protons and neutrons) are rearranged but conserved

30. Nuclear Reactions Beta emission
Note that mass number is unchanged and atomic number goes up by 1.

31. Write Nuclear Equations!
Write the nuclear equation for the alpha decay of radon- 222
222Rn  218Po He
Write the nuclear equation for the beta emitter Co-60.
60Co  60Ni e 86 84 2 -1 27 28