1. Radioactive Decay

2. Spontaneous change from an unstable nuclei to a more stable one
Releases particles, electromagnetic waves or both
Always transition from unstable to more stable

3. Characteristics of Nuclear Particles and Rays

4. Alpha Decay Nucleus with large N/Z ratio Emits an alpha particle
Basically a helium atom- 2 protons, 2 neutrons
Atomic number decreases by 2
Mass number decreases by 4

6. Beta Decay Occurs usually with large N/Z number
Neutron breaks apart into a proton and basically an electron
The electron is shot out of the nucleus as a beta particle
The proton stays in the nucleus
Atomic number increases by 1
Mass number stays the same

8. Electron Capture If nucleus has too many protons
It can absorb an electron from the electron cloud
The e- combines with the proton to make a neutron and gamma rays are given off
Atomic number decreases by 1
Mass number stays the same.

9. Positron Emission If too many protons
Proton breaks down and makes a neutron and a positron
Positron leaves the nucleus and usually hits an e-, its antiparticle
When they hit they undergo annihilation of matter emitting gamma rays
Atomic number decreases by 1
Mass number stays the same

11. Gamma Decay
High energy electromagnetic waves emitted from a nucleus as it changes from an excited state to a ground state
Energy is release when nucleons go to a lower nuclear energy shell
Usually follows other types of decay that leave the nucleus in an excited state
Atomic number stays same
Mass number stays same

13. Decay Series
Sometimes unstable nuclei go through a series of nuclear decays called a decay series
Rules for radioactive decay
All nuclear equations must be balanced

14. Transmutations Change in the identity of a nucleus
the number of protons changes
Bombardment of nuclei with charged and uncharged particles
Neutrons penetrate easily
Charged particles need energy to do so and are accelerated to make it happen
Artificial radioactive nuclei are not found in nature
Used to make transuranium elements
Elements with more than 92 protons
All are radioactive

15. Type
Atomic Number
Mass Number
Particle(s) Involved
Alpha 2 4
4 2 𝐻𝑒
Beta 1
0 −1 𝑒
Electron Capture
0 −1 𝑒, ϒ
Positron Emission
𝑒, ϒ
Gamma ϒ