1. Atomic Symbols and Isotopes
mass # K 39 19
neutrons +
protons
element Symbol
atomic #
protons
# protons = # of electrons for a NEUTRAL atom
= 20 n0
How many neutrons are present?
How many electrons are present?
19 e-

2. Complete the Table Below
Name
Symbol
Protons
Neutrons
Atomic Number
Mass Number
Carbon-14 6 8 14
Potassium-41 19 22 41
Lead-206 82
124
206

3. Unstable Nucleus = Radioactive
Radioactivity
What is radioactivity?
Radioactivity occurs when an unstable nucleus spontaneously emits fragments of the nucleus and/or energy.
Unstable Nucleus = Radioactive
Why are only some isotopes radioactive?
The ratio of protons to neutrons in the nucleus determines whether or not a nucleus is radioactive.

4. Depicting Nuclear Reaction
For nuclear reactions,
the sum of the mass numbers (top numbers) and
the sum of the atomic numbers (bottom number)
must be the same on both sides.
Mass Numbers: =
13 = 13 
Atomic Numbers: =
6 = 

5. Finding the Missing Nucleus
Mass Numbers 234 = 4 + ? ? = 230 Atomic Numbers 90 = 2 + ? ? = 88

6. Finding the Missing Nucleus
Mass Numbers 14 = 0 + A A = 14 Atomic Numbers 6 = -1 + Z Z = 7

7. Examples of Transmutation Reactions
These are all transmutation reactions because the elements on the left side are changed to produce a different element on the right side.

8. Emissions from Radioisotopes
Type of Particle Emitted
Description
Symbol
Mass
Charge
Why is it Emitted?
Alpha
A Helium
Nucleus
4 amu +2
Nucleus is too large.
Beta
A Fast Moving Electron -1
Too many neutrons
Gamma
Electromagnetic Radiation
0 amu
Too much energy
A radioisotope is a nucleus that is radioactive or unstable.

9. Writing Nuclear Decay Equations
Write the nuclear decay equation for the alpha decay of uranium-238.
Write the symbol for the type of decay.
Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow.
Mass Number: 238 = 4 + ? ? = 234
Atomic Number: 92 = 2 + ? ? = 90

10. Writing Nuclear Decay Equations
Write the nuclear decay equation for the beta decay of iodine-131.
Write the symbol for the type of decay.
Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow.
Mass Number: 131 = 0 + ? ? = 131
Atomic Number: 53 = -1 + ? ? = 54

11. Writing Nuclear Decay Equations
Write the nuclear decay equation the emission of a gamma ray from carbon-14.
Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow.
Write the symbol for the type of decay.
Mass Number: 14 = 0 + ? ? = 14
Atomic Number: 6 = 0 + ? ? = 6

12. Examples of Transmutation Reactions
These are all transmutation reactions because the elements on the left side are changed to produce a different element on the right side.

13. Decay Series for Uranium-238
This diagram shows the steps that an isotope of uranium takes to reach a stable isotope, lead-206.

14. A Closer Look at the Decay Series
Write a nuclear decay equation for what we occur to uranium-234 according to this decay series.

15. A Closer Look at the Decay Series
Write a nuclear decay equation for what we occur to lead-210 according to this decay series.

16. Writing Nuclear Decay Equations
Write the nuclear decay equation for the alpha decay of uranium-238.
Write the symbol for the type of decay.
Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow.
Mass Number: 238 = 4 + ? ? = 234
Atomic Number: 92 = 2 + ? ? = 90

17. Writing Nuclear Decay Equations
Write the nuclear decay equation for the beta decay of iodine-131.
Write the symbol for the type of decay.
Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow.
Mass Number: 131 = 0 + ? ? = 131
Atomic Number: 53 = -1 + ? ? = 54

18. Writing Nuclear Decay Equations
Write the nuclear decay equation the emission of a gamma ray from carbon-14.
Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow.
Write the symbol for the type of decay.
Mass Number: 14 = 0 + ? ? = 14
Atomic Number: 6 = 0 + ? ? = 6

19. Protecting Ourselves from Radioactive Particles

20. Positive Uses of Nuclear Chemistry
Nuclear Power
Nuclear Medicine
Kills Bacteria on Food