At GCSE level, beta decay is said to be the emission of an electron (or positron, in beta-plus decay) when an unstable nucleus transforms into a more stable nucleus. The parent and daughter nuclei are different elements with the same nucleon number (sum of neutrons and protons) but their proton numbers vary by +1 for … Continue reading Beta Decay Q-value
What is Spin?
Spin, when applied to fundamental particles, is a property rather than a description. The basic components of matter are not tiny spinning tops, like coins that are stood on edge then flicked on opposite sides to make them rotate. Instead, spin is a physical property that can be demonstrated and also a numerical value that … Continue reading What is Spin?
What is the Strong Nuclear Force?
When thinking about atoms, one of the obvious puzzles is how a nucleus stays together when it is packed with positively charged particles (protons). Why don't the positive protons simply repel each other, causing the nucleus to disintegrate? The fact that there are also neutral particles (neutrons) in the nucleus may “dilute” the positive charge … Continue reading What is the Strong Nuclear Force?
Hideki Yukawa and Meson Theory
How does the nucleus of an atom stay together? Why don’t the positively-charged protons repel each other and cause the nucleus to disintegrate? The early models of the atom imagined solid spheres, perhaps with different sizes, shapes or “colours” distinguishing one type of atom from another. Then came J J Thomson’s discovery of the electron … Continue reading Hideki Yukawa and Meson Theory
Alpha and Beta Nuclear Decay
Radioactive decay happens when an unstable nucleus changes into the nucleus of a more stable (different) element. We know that elements are defined by the number of protons in their nucleus so the only way for an atom to change into something else is by either increasing or decreasing the number of protons that it … Continue reading Alpha and Beta Nuclear Decay
Atoms: Key Facts
There's an old science joke: "you should never trust atoms because they make up everything". And that's true. Atoms aren't liars (as far as I know) but they are the smallest parts of all substances. But what else are you expected to know? Firstly, atoms are really small. The diameter of a typical atom is … Continue reading Atoms: Key Facts
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
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
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