The radioactivity notes and tutorial questions have been update.
notes
Tutorial Questions
Sunday, January 30, 2011
Wednesday, January 26, 2011
Thursday, January 20, 2011
Tuesday, January 18, 2011
Background Radiation Video
This video is from the Teachers' Domain. It is American but is still very relevant.
You can play it by clicking on the title or clicking here. The units they use are not the same as we use now.
You can play it by clicking on the title or clicking here. The units they use are not the same as we use now.
Background Radiation
Here is a link to a video which is for interest only.
Questions
What is the gas which is seeping into houses?
What does the unit 'becquerel' measure?
What is the biggest cause of lung cancer in Ireland?
Questions
What is the gas which is seeping into houses?
What does the unit 'becquerel' measure?
What is the biggest cause of lung cancer in Ireland?
Friday, January 14, 2011
Day 2 Ionising Radiations
We started of by summarising the model of the atom and alpha, beta and gamma radiation.I was impressed by how many of you had been in the blog and the Andy Darvel physics site.
We then used Flash Learning's Interactive Intermediate 2 Physics. This covers the whole course and is in the library.
After break we migrated to an IT romm to do the simulated experiments for the range of alpha, beta and gamma in air and the absorption of alpha beta and gamma by paper, aluminium and lead.
I got the impression that by the end most of you understood it.
A couple of you copied the simulations onto your USB stick - good idea. It would be a great help if all of you had a USB stick for next week.
I enjoyed the lesson today.
We then used Flash Learning's Interactive Intermediate 2 Physics. This covers the whole course and is in the library.
After break we migrated to an IT romm to do the simulated experiments for the range of alpha, beta and gamma in air and the absorption of alpha beta and gamma by paper, aluminium and lead.
I got the impression that by the end most of you understood it.
A couple of you copied the simulations onto your USB stick - good idea. It would be a great help if all of you had a USB stick for next week.
I enjoyed the lesson today.
Sunday, January 09, 2011
Thursday, January 06, 2011
Day 1 - Intro to the Course
Introduction
Terminology
What is radioactivity?
Background Radiation
Half Life
Video (if it works) about 'Barney the Horse' and another horse called 'Just another Gamble'. Although the medical treatments are on animals the same treatments are used on humans.
Introduction to your website.
The following links are interesting.
X-Ray safety Please note that this is a pdf and can take a while to load if you are not using Broadband. College computers should be OK.
Nuclear Medicine
In the last few years imaging techniques have improved enormously. The X-ray is now only one of many techniques. The equipment is expensive and radiographers are in short supply.
The link below has links to a site with many more links. You could spend a week here!
Health Protection Agency
Terminology
What is radioactivity?
Background Radiation
Half Life
Video (if it works) about 'Barney the Horse' and another horse called 'Just another Gamble'. Although the medical treatments are on animals the same treatments are used on humans.
Introduction to your website.
The following links are interesting.
X-Ray safety Please note that this is a pdf and can take a while to load if you are not using Broadband. College computers should be OK.
Nuclear Medicine
In the last few years imaging techniques have improved enormously. The X-ray is now only one of many techniques. The equipment is expensive and radiographers are in short supply.
The link below has links to a site with many more links. You could spend a week here!
Health Protection Agency
Thursday, March 04, 2010
Drawing Great Graphs
I came across this flash animation which shows how to draw a graph. It is really excellent and although the graph is chemistry it is based on the same methods which apply for physics and numeracy.
Friday, February 26, 2010
short half-life or long half life which is more dangerous?
Here is something for you to think about:
* Radioactivity - Half-life and Health Risk
Imagine radioactive material is accidentally released into the environment. Which is the most hazardous half-life for it to have? A few hours? A few years? Millions of years?
To answer this question we need to think about why radioactivity decreases with time. The simple answer is that every time a nucleus decays and releases a particle (like an alpha or beta) then there's one fewer undecayed nucleus left. For a given isotope every nucleus has the same chance of decay each second. It doesn't matter how long it's already been around for or what its neighbours are doing.
If the chance of decay is high then lots of nuclei decay each second (so lots of radiation is given off) but you quickly end up running out of undecayed nuclei. This means the half-life is short.
If the chance of decay is low then very few nuclei decay each second (so very little radiation is given off) and there are still lots of undecayed nuclei left a long time later. This means the half-life is long.
The key point is that isotopes with a very long half-life are only very weakly radioactive and isotopes that are very radioactive don't stay radioactive for long.
It turns out that the most problematic half-life for the environment is a few decades or so. Isotopes such as strontium-90 (with a half-life of about 30 years) are pretty radioactive and stick around for a time comparable to a human life-time, which gives plenty of opportunity for them to cause genetic damage.
This 'though for the day' was taken from 'furry elephant'
* Radioactivity - Half-life and Health Risk
Imagine radioactive material is accidentally released into the environment. Which is the most hazardous half-life for it to have? A few hours? A few years? Millions of years?
To answer this question we need to think about why radioactivity decreases with time. The simple answer is that every time a nucleus decays and releases a particle (like an alpha or beta) then there's one fewer undecayed nucleus left. For a given isotope every nucleus has the same chance of decay each second. It doesn't matter how long it's already been around for or what its neighbours are doing.
If the chance of decay is high then lots of nuclei decay each second (so lots of radiation is given off) but you quickly end up running out of undecayed nuclei. This means the half-life is short.
If the chance of decay is low then very few nuclei decay each second (so very little radiation is given off) and there are still lots of undecayed nuclei left a long time later. This means the half-life is long.
The key point is that isotopes with a very long half-life are only very weakly radioactive and isotopes that are very radioactive don't stay radioactive for long.
It turns out that the most problematic half-life for the environment is a few decades or so. Isotopes such as strontium-90 (with a half-life of about 30 years) are pretty radioactive and stick around for a time comparable to a human life-time, which gives plenty of opportunity for them to cause genetic damage.
This 'though for the day' was taken from 'furry elephant'
Sunday, February 03, 2008
Alexander Litvinenko
Alexander Litvinenko was the former Russian spy who died due to poisoning by Polonium-210.
After reading the Health Protection Agency Report answer the following questions.
What type of radiation killed Alexander Litvinenko?
When does this type of radiation become a radiological hazard?
Are the hospital staff who treated Alexander Litvinenko at risk?
After reading the Health Protection Agency Report answer the following questions.
What type of radiation killed Alexander Litvinenko?
When does this type of radiation become a radiological hazard?
Are the hospital staff who treated Alexander Litvinenko at risk?
Monday, January 28, 2008
Radioactivity Crossword
Click here for a crossword to help with your revision for the first part of the assessment.
If you want to leave a comment post as anonymous.
If you want to leave a comment post as anonymous.
Half Life Simulation
Clicking on the title bar above will take you to a Java Applet which simulates radioactive decay. The simulation gives a good idea of what is happening.
- What is meant by the term 'half life'?
- Choose any 5 of the examples and watch the applet and state the their half life.
- Can the number of radioactive atoms ever reach zero?
- What do think the term 'daughter nuclide' means?
- What happens to the total number of atoms in the sample?
Medical Physics Site
Here is a link to a site which explains radiotherapy as well as other treatments. The simulations are pretty good. Obviously it is not in the assessment but if you need a break and want to see how radiotherapy works click this link.
Thursday, January 24, 2008
Half Life Simulation
The simulation we used was from Explorelearning. You can use each Gizmo for 5 minutes before it 'times out'. If you want to use them for longer register for a months free trial.
To find the one we used type half life in the 'search' then 'launch gizmo'. Enjoy!
To find the one we used type half life in the 'search' then 'launch gizmo'. Enjoy!
Tuesday, January 15, 2008
Lesson on Atomic Stucture
Here is another lesson on the structure of the atom. Clicking on the title will also take you there.
Monday, January 14, 2008
Brilliant Website - S-Cool
The S-Cool website cover virtually all of Introducing Radioactivity and just the right level. The website has lots of good physics material but you only need the know the material linked from here. To go to the radioactivity section either click here or on the title bar above.
