Nuclear Chemistry: Unit 5

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Most chemical reactions involve
The exchange or shafing of electrons which does not affect the nucleus
How is nuclear chemistry different than other chemical reactions?
Bc it involves changes in the nucleus
When the nucleus of one element is changed into the nucleus of a different element
Which means the number of protons is changing
(doesn’t happen at your house, not normal)
What determines the stability of a nucleus?
Ration of neutrons to protons
For elements with low atomic numbers the ration is close to
For elements with higher atomic numbers they need
More neutrons than protons
All nucleiwith atomic numbers greater than ___ are unstable
They are radioactive
Wrong ratio of neutrons to protons
An unstable nucleus decays spontaneously to form protons that are more stable, realeasing radiation
Radioactive isotopes
When a nucleus decays it emits radiation in the form of either
Alpha particles
Beta particles
Gamma rays
Alpha particle
Helium nucleus with two protons and two neutrons
Beta particle
Electrons that came out of the nucleus
Electrons with a positive charge
(Atoms like electrons, same thing but with a positive charge)
Gamma rays
Penetrating power
Ability to go through matter
-penetrating power
4 u
4 2 He
Low (biggest mass)
-penetrating power
0 u
0 -1 e
-penetrating power
0 -1 e
-penetrating power
0 0 y
High (no mass)
Alpha particles
Are deflected toward the negative place
Are deflected toward the positive plate
Gamma rays
Not deflected- no charge
Beta particles
Are deflected more than alpha particles because they have a smaller mass (lighter)
Can be harmful to living things
How can radiation harm living things?
1. Can ionize (cause to form ions which can damage tissue)
2. Can cause cells to be unable to carry on normal functions and can lead to cell death
3. Can cause mutations (cancer)
Alpha emitter
Unstable nucleus that emits an alpha particle
Usually heavy nuclei with atomic numbers greater than 82
83 and up are considered
Radioactive, unstable
Alpha: Atomic number
Decreases by 2
Alpha: Mass number
Decreases by 4
Alpha: number of neutrons
Decreases by 2
Beta emitter
An unstable nucleus that emits beta particles
How can this happen?
The neutron splits into a proton and electron
Too many neutrons, so they make more protons and electrons. They only need protons so the electron comes out of the nucleus
Beta: atomic number
Increases by 1
Beta: mass number
Stays the same (bc the protons goes up so neutrons goes down)
Beta: number of neutrons
Decreases by 1
Positron emitter
Unstable nucleus that emits a positron
How can this happen?
The proton splits into a neutron and a positron
Positron: atomic number
Decreases by one
Positron: mass number
Stays the same
Positron: number of neutrons
Increases by one
Categories: Nuclear Chemistry