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
Radiation and Altitude
The discovery of radioactive rocks was unexpected but when physicists attempted to discover how far the new “penetrating rays” could reach, they were in for an even bigger surprise. Henri Becquerel’s discovery that uranium salts emit penetrating radiation was one of science’s great “accidents”. Uranium was first identified in 1789 but it was a century … Continue reading Radiation and Altitude
Key Facts: Electromagnetic Waves
Having previously covered waves in general (https://physbang.com/2023/04/13/key-facts-waves/) it is now time to look at electromagnetic waves in particular as this is a topic in its own right. Electromagnetic waves are created by the movement of electrons in different situations. The electrons can be moving in an electric circuit, to produce or receive radio waves, or … Continue reading Key Facts: Electromagnetic Waves
Radioactivity mini-test
There is a short online test that you can use to check your understanding of the key facts covered in the radioactivity topic for GCSE Physics. The test, available here, is hosted on liveworksheets.com so you will be able to see your score immediately after completing the test. Note that Q4 is not marked because … Continue reading Radioactivity mini-test
Half-life, Applications and Precautions
Radioactive decay is a random process. This means that if you were to observe a lot of unstable (radioactive) atoms, you would notice that they undergo nuclear decay at unpredictable moments. But if you extended your observations for a longer period you would spot an underlying pattern. Although it is impossible to predict when one … Continue reading Half-life, Applications and Precautions
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: 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
Revising Atomic Structure
Tucked away inside a website of astronomy resources I have just found a brilliant little tool for revising atomic structure, which is required knowledge for AQA Trilogy (and other) GCSE examinations in both physics and chemistry. You can find it at https://astro.unl.edu/newRTs/nuclei/. The assessment is a two-part, drag-and-drop ranking exercise where you have to rearrange … Continue reading Revising Atomic Structure
Atomic Structure and the Periodic Table
There are various GCSE topics where physics and chemistry intersect, so revising these areas can have a double benefit. One such example is atomic structure. Helpfully, BP Educational Services has just released a new set of resources to help you revise this content as you prepare for this summer's examinations. To access the free knowledge … Continue reading Atomic Structure and the Periodic Table
Mr Tarrant's physbang 'blog 