Compound Interest: Physical Chemistry

30 Years Since Chernobyl – How Nuclear Reactors Work

April 26, 2016 8Comments 0Likes 284Views

Infographic on how nuclear reactors generate electricity. A schematic of the reactor is shown. Nuclear fission reactions generate hear which heats water and turns it into steam. The steam drives a turbine, spinning a generator and producing electricity. The steam condenses back into water and can be recycled through the reactor. The fission reactions involve uranium-235 atoms, which are split by neutrons to release energy and more neutrons which produce a chain reaction. Control rods control the reaction by absorbing neutrons, while moderators slow neutrons down so they can be absorbed by uranium atoms. Fission products remain radioactive for many years and must be stored safely. — Click to enlarge

Early in the morning on 26 April 1986, a safety system test at the Chernobyl power plant in Pripyat, now part of Northern Ukraine, ended in a nuclear disaster with catastrophic consequences for both those working at the plant and those living in the surrounding area. The narrative seems to be a classic cautionary tale against the utilisation of nuclear reactors to generate power, but the reality is more nuanced. Here, we look at how nuclear reactors work generally, what led to the accident at Chernobyl 30 years ago, and the differences between Chernobyl and modern reactors.

What Temperature Does Water Boil At? Boiling Point & Elevation

March 22, 2016 9Comments 3Likes 351Views

An infographic on why the temperature at which water boils can vary depending on elevation. The boiling point of water at a range of elevations is shown. A liquid will boil when its vapour pressure is equal to the atmospheric pressure; vapour pressure can be thought of as the tendency of molecules to escape the liquid’s surface into the gas phase.
At lower pressures, molecules escape more easily, as the vapour pressure required for them to do this is lower. — Click to enlarge

Water always boils at 100˚C, right? Wrong! Though it’s one of the basic facts you probably learnt pretty early on back in school science lessons, your elevation relative to sea level can affect the temperature at which water boils, due to differences in air pressure. Here, we take a look at the boiling points of water at a variety of locations, as well as the detailed reasons for the variances.

Making Reactions Faster: Factors Affecting Rates of Reaction

February 17, 2016 5Comments 1Like 318Views

How different factors can affect how quickly a reaction happens is a common topic in the chemistry curriculum. This graphic serves as a convenient summary for teachers and students alike of what these different factors are, and how and why they affect the rate of a reaction. However, it’s not only of interest to those teaching or learning about chemistry; as we’ll see, knowledge of these factors can have some everyday applications too!

A Guide to Different Common Types of Radiation

A Guide to the Different Types of Radiation

September 10, 2015 10Comments 2Likes 308Views

We’re venturing tentatively into the border region between chemistry & physics today, with a look at some of the different types of nuclear radiation. These types vary in their composition, characteristics, and uses, but here’s an attempt to sum up the most common in one succinct graphic.

Acids, Alkalis, and the pH Scale

July 9, 2015 14Comments 1Like 361Views

Acids and Alkalis - The pH Scale — Click to enlarge

The pH scale is something we’re all familiar with; most people will remember it from school chemistry lessons. It’s the scale used to rank how strong an acid (or alkali) a solution is. The colours associated with each number correspond to the colour that universal indicator turns in solutions of that particular pH. A fair proportion of people probably don’t know the chemistry behind the pH scale, though – where exactly do these numbers come from?