This document discusses natural radioactivity and the different types of natural nuclear transmutations that can occur. It explains that larger atoms are generally more unstable due to having a greater proton to neutron ratio further from 1:1. The three main types of natural transmutations discussed are alpha decay, beta decay, and gamma decay. Alpha decay involves emitting an alpha particle, beta decay involves emitting an electron or positron, and gamma decay involves emitting high energy photons without any particle emission. Examples of writing nuclear reactions are provided to identify the missing particle.

1. A. Natural Radioactivity
Many nuclei of atoms are very stable, others are
unstable and will decay
Based on the ratio of protons to neutrons
Further from a 1:1 ratio, more likely to decay
12 C 6 protons, 6 neutrons stable
6
13 C 6 protons, 7 neutrons unstable
6
Larger atoms are generally more unstable
No stable isotopes past Bi All are radioactive

2. Natural Transmutation Atom releases energy (usually as a
particle) and transforms into a different element
C
14
N
14
The nucleus breaks down with no outside interference (natural)
A. Types of Natural Transmutations
1. Alpha Decay α
Releases an alpha particle 2 protons and 2 neutrons
Written as 4 He Same as a Helium nucleus
2
Low energy particle
Little ionizing power Cannot break apart molecules well
Low penetrating ability, blocked by paper

3. 2. Beta particle β
- Releases a beta particle and energy from the nucleus
- Actually it is an electron
0 No noticeable mass
Opposite charge of a proton
e
-1
- a neutron breaks down into an electron and a proton
- the electron is then released from the nucleus
Moves faster than alpha, almost to the speed of light
More damaging, - Higher penetrating ability and ionizing
ability blocked by thin sheets of lead
3. Gamma decay γ
No particle, just a release of energy
Energy is similar to high energy x-rays
Very high ionizing ability and penetrating ability
Can penetrate several cm of lead, blocked by thick lead

5. Chart N - Lists types of decays for many nuclei
B. Writing Nuclear Reactions
We can determine what particles are present by what is
left after the decay 222
Rn
86
86
226
Ra --> 4 He + _________
88 2
Since we lost 4 nuclear particles We have 222 left
Since we lost 2 protons We have 86 left
To determine the identity, look at the atomic number
and match it to the periodic table

7. Examples - Determine the missing nuclear particle
210
Bi
A. 210Pb --> ______ + 0e beta
82
83 -1
0
B. 214
Bi --> 214
Po + _______
e beta
4 -1
83 84
He
C. 214Po --> _________ + Pb
210 alpha
2
206
D. 206Tl -->
84
0
e + ________
Pb 82 beta
82
Now 81 back-1and label the reactions as alpha or beta decay
go
Use chart N to determine the products of the following
A.
85
Kr 0
e + 85 Rb Beta decay
36 -1
37
B. 232
Th 4
He +
228
Ra Alpha decay
88
2
90