Nuclear fission (see here) is caused when an atom absorbs an extra neutron, causing the nucleus to split apart. The resultant nuclear reaction releases more neutrons, which can go on to cause further fission events. This sequence, where released neutrons go on to cause further fissions, is known as a chain reaction. If the number … Continue reading Chain reactions
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SP1 – Specification
Topic 1 isn't really a topic in itself so much as the foundations that will be assumed to be in place for every topic that follows. It covers the key skills you need to know regarding units of measurement and prefixes that are used to increase or decrease the size of a unit. It also … Continue reading SP1 – Specification
Isotopes
We have previously seen (in this post) that an element always has a fixed atomic number but its atoms can have different atomic mass values. This is because most elements can exist in different forms with different numbers of neutrons - but always the same number of protons and electrons. These different forms are known … Continue reading Isotopes
Atomic Number and Atomic Mass
When you learned about the Periodic Table during KS3, you were told that it lists all the elements in order of their atomic number. You should also have learned that every element has two numbers; the smaller value is the element's atomic number and the larger value is the element's atomic mass. The value for … Continue reading Atomic Number and Atomic Mass
SP6 – Tips for the Test
The attached document (click here) gives the top 12 things you should revise for the end-of-topic test. It is NOT a comprehensive list of everything you will need to know about radioactivity for the final GCSE examination but it is a good place to start when revising for the school test. If you want the … Continue reading SP6 – Tips for the Test
SP6 – Specifications
Edexcel's specification that lists everything you need to know about the Radioactivity topic is contained in this document.
How much Iodine-131 remains?
The television drama Chernobyl inspired a series of articles in the August 2019 issue of Physics World. One of the articles was an interview with Richard Wakeford, editor-in-chief of Journal of Radiological Protection, discussing why the assessment of radiation risk is so difficult. Responding to a question asking whether access to some areas around Chernobyl … Continue reading How much Iodine-131 remains?
Neutrons and Nuclear Fission
Early models of the atom considered only two types of particles; protons and electrons. We now need to realise that there is a third particle in the nucleus as this particle turns out to be the key to using nuclear processes for electricity generation. Although natural radioactive decay happens spontaneously, it does not transfer energy … Continue reading Neutrons and Nuclear Fission
Units and Equations
Units of measurements that are created by combining other units often demonstrate how to perform the appropriate calculations. That may sound a bit confusing but knowing how this works can be very useful when answering exam questions. Let's look at what this actually means... To calculate speed we need to measure a change in distance … Continue reading Units and Equations
What are atoms?
The idea of an atom arises from a simple question: is it possible to keep breaking a piece of matter into smaller and smaller pieces or do you eventually get to the smallest piece of matter that cannot be divided any further? It turns out that the breaking cannot go on forever and there is … Continue reading What are atoms?
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