1. Day 8
Isotope Quiz
Chapter 24 Section 1
Band of Stability Work Sheet

2. Daily Reaction Na(OH) + CuCl2  NaCl + Cu(OH)2 Questions:
The periodic table is also arranged by increasing atomic number or the number of protons in the nucleus. It is the number on top of each symbol.
Elements can be combined to form single units such as (OH). OH is call hydroxide and is an important component of a “base”. A base is opposite of an acid and can still be very dangerous.
Questions:
What type of reaction is this?
Using your periodic table identify the symbols and names.
What row is each element in.
Identify the atomic number.

3. Chapter 24 - Nuclear Chemistry
Characteristics of Chemical and Nuclear Reactions
Chemical Reactions
Nuclear Reactions
Occur when bonds are broken and formed.
Occur when nuclei emit particles and/or rays.
Atoms remain unchanged, though they may be rearranged.
Atoms are often converted into atoms of another element.
May involve protons, neutrons, and electrons
Involve only valence electrons.
Associated with small energy changes.
Associated with large energy changes.
Reaction rate is influenced by temperature, pressure, concentration, and catalysts.
Reaction rate is not normally affected by temperature, pressure or catalyst.

4. Radioisotopes Isotopes of atoms with unstable nuclei
Name the 3types of radiation that you know
Alpha
Beta
Gamma

5. Properties of Alpha, Beta and Gamma Radiations
The Differences
Properties of Alpha, Beta and Gamma Radiations
Property
Alpha(α)
Beta (β)
Gamma (γ)
Composition
Alpha particles
Beta Particles
High-energy electromagnetic radiations
Description of radiation
Helium nuclei
Electrons
photons
Charge 2+ 1-
Mass
6.64 x
9.11 x
Approximate Energy
5 MeV
0.05 to 1 MeV
1 MeV
Relative penetrating Power
Blocked by Paper
Blocked by metal foil
Not completely blocked by lead or concrete

6. The Equations
Alpha Radiation
Beta Radiation
Gama Radiation

7. 2 More types of radiations
Positron Emission
A proton is converted into a neutron and a positron.
A positron is a positively charged electron.
Electron Capture
An electron and proton combine to form a neutron

8. Nuclear Stability Why are atoms unstable? Proton to neutron ratio
What are Nucleons
Positively charges protons
Neutral neutrons

9. Half Lives – Radioactive Decay
Half Life – time required for half of the nuclei to decay into its products.
3 Steps
Determine the number of half lives by
Multiply the the amount you started with by the number of (½) lives.
That will tell you how much is left.

10. Half Life Example... Formula
Strontium – 90 has a half life of 29 years. In 58 years how much strontium – 90 will be left if you started with 20 g?
Follow your steps
Determine how many Half lives. 58/29 = 2
Multiple the number of half lives by what you started with.
20g (½ ) (½) = 5g remaining
Formula
N = No (½ )...
N = How much remains
No = How much I started with (Orignal amount)
(½ ) = the half lives

11. The Band of Stability
All elements with atomic numbers greater than 83 are radioactive!
Isotopes with a ratio of neutrons to protons above 1.5 are unstable and undergo radioactive decay.
Band of Stability Worksheet for homework

12. Look Ahead… Homework Problems: Day 9 - Chapter 24 Section 2
Day 10 – Quiz: Radioactive Decay