People often ask why chemical elements are represented by the symbols they have been given. Some are obvious; H, C, N and O could only really be hydrogen, carbon, nitrogen and oxygen. Similarly, Zn is fairly obvious as zinc, Ar is clearly argon and Es makes sense as Einsteinium (once you know that name exists). … Continue reading Element Names
Radioactivity Summary
The test may be done but the learning doesn't stop! I've found a great summary of the basics that you need to know about radioactivity, courtesy of the Lawrence Berkeley National Laboratory. The crucial page is at https://www2.lbl.gov/abc/Basic.html but you may like to take a look at the entire ABC's of Nuclear Science section. For … Continue reading Radioactivity Summary
Nuclear Reactor Components
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
Irradiation and Contamination
There are two ways in which radioactive materials can affect the surrounding environment; irradiation and contamination. Understanding the differences between these two effects is important in terms of the precautions that must be taken when handling radioactive sources and also when storing radioactive waste. Irradiation refers to the transfer of energy (via ionising radiation) without … Continue reading Irradiation and Contamination
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
Experimental data
One of the most important skills that is required for success in physics is the ability to handle experimental data in an appropriate way. This includes everything from correct use of units and equations to identifying anomalies, finding averages and recording calculations with the proper number of significant figures. All of these skills are tested … Continue reading Experimental data
SP8-9 Forces Doing Work (mini-test)
The first module of Y11 is now complete and to help you prepare for the assessment I have created a mini-test, complete with mark scheme and explanation. You can access the test by clicking here and the mark scheme is here. Work through the questions then check your answers to spot any errors or misconceptions … Continue reading SP8-9 Forces Doing Work (mini-test)
Forces moving forces
The idea of work done can be extremely useful when designing machines that make life easier and sometimes even enable us to do things that are "impossible". For example, it is fair to say that most humans are not capable of lifting masses of a tonne (1000 kg) or more. And yet that is indeed … Continue reading Forces moving forces
Is there anybody out there?
Nobody knows whether there is intelligent life elsewhere in the Universe, and some people joke that it may not even exist here on Earth, but it's still interesting to consider the probability of there being extra-terrestrial life out in space. The long-established basis for calculating the likelihood of Earthlings detecting radio signals from life elsewhere … Continue reading Is there anybody out there?
