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
Atoms: Vital Statistics
In a previous article, I recapped the key facts you need to know about atoms. Here we will look at the numerical information you need to remember and the concept of isotopes. The table below lists the essental information you need to know about the three sub-atomic particles; protons, neutrons and electrons. There is an … Continue reading Atoms: Vital Statistics
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
Non-binary electrons
On the final day of term, a member of my form tested me with a series of science jokes, the first of which was; “Why does a beef burger have less energy than a steak?” Pause here if you want to come up with your own solution. I must admit that I didn’t guess the … Continue reading Non-binary electrons
Electron Shells
The idea of electron shells is essential in chemistry and also plays an important part in various areas of physics so needs to be discussed in its own right. But before we look at electron shells let's be clear that this is just a model - a way of imagining what is going on inside … Continue reading Electron Shells
Atoms – basic ideas
The original idea of an atom came from asking a very simple question: if you take a substance and cut it into smaller and smaller pieces, is there a limit to how many times you can keep cutting it into smaller pieces? When this question was originally asked, back in ancient Greece around 400 BC, … Continue reading Atoms – basic ideas
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
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
Try This At Home (IoP)
You could be studying physics every day but it would be better to have some down time! So here are some ideas for experiments that you can do at home when you are taking a break from your studies. These things aren't rocket science; they're about waves, forces and the shape of space (actually a … Continue reading Try This At Home (IoP)
Mr Tarrant's physbang 'blog 