1. Chapter 4
Structure of the Atom

2. Radiation
Radioactivity is the spontaneous emission of particles or energy due to nuclear disintegration.
There are three types of natural radiation:
Alpha
Beta
Gamma

3. Do Not Copy

4. Radiation Alpha Particle (Helium Nucleus)
Made of 2 protons & 2 neutrons
Positive charge
Symbol: α

5. Radiation Beta Particle
Made of high speed electrons emitted from the nucleus of the atom
Negative charge
Symbol: β

6. Radiation
Gamma rays
Made of high energy x-rays
No charge
Symbol: γ

7. 4.4 Unstable Nuclei and Radioactive Decay
The symbol of elements in nuclear reactions is often written as AZX, where A is the mass number, Z is the atomic number, and X is the symbol of the element.
For example Uranium- 238 is written as:
23892U

8. Radioactive molecules decay (decompose) by releasing alpha, beta, and gamma radiation.
In alpha decay, 2 protons and 2 neutrons are lost (42He)
In beta decay, electrons from
the nucleus are lost (0-1e)

9. During nuclear decay, the number of protons in the atom changes, this is known as transmutation.
If the number of protons changes, the identity of the atom also changes.

10. EX1: Complete the following alpha decay equations:
a. 189F  42He + ____
b Th  42He + ____

11. EX2: Complete the following beta decay equations:
a. 4924Cr  0-1e + ___
b. 2712Mg  0-1e + ___

12. EX3: Identify the type of nuclear decay:
a Rh  10046Pd + ___
b Ra  20986Rn + ___

13. PP1: Complete the following nuclear equations:
a. 32He  0-1e + ___
b. 93Li  94Be + ___
c Bi  42He + ____
d Po  19582Pb + ___
e. 6130Zn  0-1e + ___
f U  23690Th + ___
g Fm  Md + ___
h. 8037Rb  42He + ____