1. Nuclear

2. Isotopes Isotopes are atoms of an element with different mass numbers
They have the same number of protons, but different numbers of neutrons
Many Isotopes are radioactive

3. Isotopic symbols
they are written by writing the symbol of the element and then to the left side of the symbol write the mass number on top and the number of protons below

4. Radioactivity The spontaneous decay of the nucleus of an atom
When an atom decays energy and particle are given off from the nucleus

5. Band of Stability n = p Number of neutrons Number of protons 160 150
140
130
120
110
100 90 80 70 60 50 40 30 20 10
Band of Stability
n = p
Number of neutrons
The band of black squares, which shows the stable nuclides, is known as the band of stability. In general, the further a nuclide is from the band of stability, the shorter the half-life of the nuclide.
No stable isotopes are known for elements with atomic numbers higher than 83 (bismuth).
Stable nuclides
Naturally occurring radioactive nuclides
Other known nuclides
Number of protons

6. Nuclear Decay Why nuclides decay… b a
need stable ratio of neutrons to protons
120
100 80 60 40 20
Neutrons (A-Z)
Protons (Z)
P = N b
stable
nuclei a
e-capture or
e+ emission
Courtesy Christy Johannesson
DECAY SERIES TRANSPARENCY

7. Nuclear Decay Why nuclides decay… b a
need stable ratio of neutrons to protons
stable
nuclei
P = N b
stable
nuclei a
P = N
120
120
e-capture or
e+ emission
100
100 80 80 60 60
Neutrons (A-Z)
Neutrons (A-Z) 40 40 20 20 20 40 60 80
100
120 20 40 60 80
100
120
Protons (Z)
Protons (Z)

8. Discovery of the Neutron+ +
Chadwick is credited with the discovery of the neutron
as a result of this transmutation experiment.
James Chadwick bombarded beryllium-9 with alpha particles,
carbon-12 atoms were formed, and neutrons were emitted.
Dorin, Demmin, Gabel, Chemistry The Study of Matter 3rd Edition, page 764

9. Types of Radiation Type Symbol Charge Mass (amu) Alpha particle 2+
Beta particle 1-
Positron 1+
Gamma ray

11. Nuclear Decay Numbers must balance!! Alpha Emission parent nuclide
daughter
nuclide
alpha
particle
Numbers must balance!!
Courtesy Christy Johannesson

12. Nuclear Decay Beta Emission electron Positron Emission positron
Courtesy Christy Johannesson

13. Half-Lives of Isotopes
Half-Lives and Radiation of Some Naturally Occurring Radioisotopes
Isotope Half-Live Radiation emitted
Carbon-14
5.73 x 103 years b
Potassium-40
1.25 x 109 years
b, g
Radon-222
3.8 days a
Radium-226
1.6 x 103 years
a, g
Thorium-230
7.54 x 104 years
a, g
Thorium-234
24.1 days
b, g
Uranium-235
7.0 x 108 years
a, g
Uranium-238
4.46 x 109 years a

14. Half-Life Plot Half-life of iodine-131 is 8 days20
Half-life of iodine-131 is 8 days 15
1 half-life
Amount of odine-131 (g) 10 16
2 half-lives 5 24
3 half-lives 32
4 half-lives
etc… 40 48 56 8
Time (days)
Timberlake, Chemistry 7th Edition, page 104

15. Half-Life Half-life (t½)
Time required for half the atoms of a radioactive nuclide to decay.
Shorter half-life = less stable.
1/1
Newly formed
rock
Potassium
Argon
Calcium
Ratio of Remaining Potassium-40 Atoms
to Original Potassium-40 Atoms
1/2
1/4
1/8
1/16
1 half-life
1.3
1 half-lives
2.6
3 half-lives
3.9
1 half-lives
5.2
Time (billions of years)

16. Half-Life Half-life (t½)
Time required for half the atoms of a radioactive nuclide to decay.
Shorter half-life = less stable.
1/1
1/2
1/4
1/8
1/16
Ratio of Remaining Potassium-40 Atoms
to Original Potassium-40 Atoms
1 half-life
1.3
1 half-lives
2.6
3 half-lives
3.9
5.2
Time (billions of years)
Newly formed
rock
Potassium
Argon
Calcium

17. Fission
Fission is a manmade process for splitting atoms where a nucleus is made unstable by bombarding it with a neutron, which starts and a chain reaction

18. Fission
Fission releases an enormous amount of energy with no pollution
However it also leaves the nucleuses of the bombarded atoms unstable and radioactive for many years

19. Uses for fission
Fission is used in weapon- the atomic bomb uses fission
Fission is also used by nuclear power plant to produce electricity
The energy that comes from fission is explained by Einstein’s equation
E= mc2

20. Fusion
The process of atomic nuclei combining with each other when they collide at very high speeds.
Releases even more energy than Fission.
Scientist are still unable to control this reaction.
This is the reaction that powers the sun

21. Fusion

22. QuickWrite
Explain the difference between Alpha, Beta, Gamma Radiation. Use words like Decay, Isotopes, Electron, and Positron.