1. Nuclear Energy
Atoms and Isotopes

2. Isotopes
Recall:
Isotopes are atoms of the same element with the same atomic number, but different mass number.
Hydrogen
Deuterium
Tritium

3. Standard Atomic Notation
MASS NUMBER A X
ELEMENT SYMBOL Z
ATOMIC NUMBER

4. Radioisotopes
Some isotopes are considered to be unstable: meaning they spontaneously change their structure by releasing radiation.

5. Nuclear Reactions
Nuclear reactions occur whenever there are changes in the nuclei of atoms, sometimes resulting in completely new elements.
To understand these nuclear reactions, we must understand the nature of the nucleus and the subatomic particles that are involved.
TRANSMUTATION

6. Nucleon: A proton or a neutron
Nuclear Reactions
Strong nuclear force
Electrostatic force
Electrostatic force + +
Nucleon: A proton or a neutron

7. There are 3 types of radioactive decay:
If the electrostatic force is greater than the strong nuclear force, the nucleus spontaneously changes and releases energy – this is radioactive decay.
There are 3 types of radioactive decay:
Alpha decay (α-decay)
Beta decay (β-decay)
Gamma decay (γ-decay)

8. Alpha Decay
A helium nucleus (2 protons and 2 neutrons) is emitted from a large nucleus.

10. Beta Decay
A beta particle (an electron or a positron) is released or captured.
β-negative decay:
Strong nuclear force much greater than electrostatic force…must increase electrostatic force.
How?
A neutron spontaneously decays into a proton and an electron

12. β-positive decay:
A proton spontaneously decays into a neutron and an positron

14. Electron capture:
An electron is absorbed by a nucleus and combines with a proton to form a neutron.

16. Gamma Decay
Occurs whenever an excited nucleus spontaneously releases energy in the form of a gamma ray (a photon of light), in order to return to a lower energy state.