Class notes
RADIACTITVITY
- Course
- Institution
Lecture notes of 5 pages for the course Edexcel at Edexcel (.)
[Show more]
Seller
Follow
aahilkamran
Content preview
RadioactivityBecquerel → unit of radioactivity
Centimeter → unit of length
Hour, minute, second → unit of time
bigger number is the mass number (proton+neutron)
smaller number is the atomic number (number of proton)
symbol is the Element Symbol
Isotope: are atoms of the same element with the same proton number and different neutron
number
An atom is radioactive because their are too many neutrons in the nucleus which makes it unstable,
the unstable nucleus will emit radiation so it helps it become stable
Radioactive decay: unstable element decay into other elements by emitting radiation
3 types of radiation:
- Alpha
- Beta
- Gamma
- Emit neutrons
Alpha:
- A heavy nucleus emits an alpha particle
- It has a helium nucleus (2 neutrons 2 protons)
- Stopped by a sheet of paper
- Highly ionizing
- Weekly penetration (large particles)
- Take 4 off the mass number
- Take 2 off the atomic number
- If alpha enters it causes mutation, cancer
, Beta:
- A neutron turns into a proton and emits a beta particle (electron)
- Fast moving electrons
- Negative charge
- Much smaller mass than alpha
- The smaller mass makes it:
- less highly ionizing than alpha
- less penetrating than gamma
- Stopped by thin sheet of aluminum
Mass number stays same
Atomic number goes up by 1
Gamma:
- Waves Electromagnetic spectrum
- Emitted after alpha or beta radiation so the nucleus gets rid of energy
- High frequency
- Weakly ionizing
- Highly penetrating
- Can be stopped by thick lead or concrete
Ionising means: potential to gain or lose electron
Penetrating means how far the radiation travels before it stops
Emitting neutrons:
- If there are too many neutrons (unstable
- It throws out neutron
- To increase stability
- Subtract 1 from mass number
Activity: rate of decay of all the isotopes in the sample
OR
The number of decays that occurs per unit time
1 Bq = 1 decay per second
Half life: is the time taken for the number of radioactive nuclei in a sample to halve
OR
The time taken for the number of decays or activity to halve
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller aahilkamran. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $10.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
76799 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now