In a highly simplified view of nuclear fission reactors, we can reduce the key elements to just two components that control the chain reaction. Control rods are used to reduce the number of free neutrons and the moderator is used to slow down the neutrons so that they can be captured by other nuclei to … Continue reading Nuclear Reactor Components
Radioactivity: Basics and Test
This post highlights the fundamental knowledge and key skills that form the basics of radioactivity. There is also a short online test for you to check your understanding. The first things you need to know are descriptions of the atom (how models have changed with time) and what causes "radioactivity". These two fundamentals are covered … Continue reading Radioactivity: Basics and Test
Rutherford’s Gold Foil Experiment
Ernest Rutherford is credited with proving that atoms have a small, dense and positively charged nucleus surrounded by negatively charged electrons. To be exact, it was Ernest Marsden who carried out the very first version of the famous gold foil experiment while working under the direction of Rutherford and Hans Geiger. Rutherford was not even … Continue reading Rutherford’s Gold Foil Experiment
Black Holes
In our course, we cover Black Holes only as the final product of a collapsed super-massive star but if you want to know more about these fascinating objects then I highly recommend the ten-minute video by Perimeter Institute. To view the video, go to https://www.youtube.com/watch?v=TfdviKnUZOA&list=PL1608DAAD37A04B35 The same collection of videos also has a great six-minute … Continue reading Black Holes
Balancing Nuclear Equations
An easy way to pick up marks in the GCSE Physics exam is by balancing nuclear equations. To do this, you need to apply the law of the conservation of mass, which says the total mass before a nuclear change takes place is equal to the total mass after the change has occurred. This is … Continue reading Balancing Nuclear Equations
Nuclear Fission Processes
Nuclear fission is the process whereby a nucleus is split into two smaller nuclei. Fission happens when a nucleus absorbs an extra neutron and becomes highly unstable, instantly splitting apart. The starting nucleus is known as the 'parent' and the split fragments are known as 'daughter' nuclei. The parent nucleus does not split exactly in … Continue reading Nuclear Fission Processes
Moderators and Control Rods
If nuclear fission processes are used to generate electricity in a nuclear power station, it is absolutely vital to manage the neutrons that are released during nuclear fission so that their number remains constant and energy is released at a constant rate. This management is achieved using control rods and a moderator, which serve two … Continue reading Moderators and Control Rods
Chain reactions
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
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
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