What’s the difference between an expression and an equation?

Well, I’ll answer that in a moment. More generally, you should be familiar with algebraic terminology since relevant words are used in exam questions—you need to know exactly what they mean. Let’s start at the beginning and build up… Constants and variables A constant is a fixed number, such as 2. A variable is a letter which can take on different values, such as $x$. To complicate things, letters can sometimes be used to stand for constants! For example, I can define ...

Electric Vehicles in China

China wants to lead the world in the manufacture and use of clean-energy cars, and to achieve this it will need to ensure research and development in battery production. Batteries have become vital to the manufacture of clean energy cars. As part of China’s industry development plan (April 2017), the government pledged to promote research and development of key battery cell parts and improve management structures in the industry. Batteries are at the heart of clean energy vehicles because they are ...

Muhabbat Sharapova, Mathematician – and Hero of Uzbekistan

To be named as a "Hero of Uzbekistan" is to be awarded the highest national honour in that country. Recently, Muhabbat Sharapova, one of the country's top mathematicians, received the award - not for her mathematical prowess, but because she has turned down job offers from many leading universities and institutions in favour of remaining a maths teacher in her small home town. In an interview for the BBC's 100 women initiative, she says: "Mathematics is the mother of all sciences." ...

Collision theory and mechanisms – linking it together

I’ve just started teaching the kinetics topic to my students and so far we have focussed on the collision theory. Have you heard of this? The collision theory explains to us what happens during chemical reactions in terms of the collision of particles. In order for a chemical reaction to occur, particles need to come together (collide) with sufficient energy (speed). This is called the activation energy (and is defined as the minimum amount of energy required for a chemical reaction). If ...

Chocolate industry destroying rainforest in Cote d’Ivoire

The world’s chocolate industry is driving deforestation on a devastating scale in West Africa. As global demand for chocolate booms, ‘dirty’ beans from deforested national parks have entered big business supply chains. As much as 40% of the world’s cocoa comes from Cote d’Ivoire, and the rainforest cover has been reduced by more than 80% since 1960. The chocolate industry has many small-scale farmers who grow cocoa on plantations, many of which are illegal as they are in national parks or protected ...

Making esters

We carried out a great lab in school today, making esters. Have you ever done this? What was good about it was that we used a good range of reagents and got some very different results. I set the class up with a range of alcohols and carboxylic acids and told them it was up to them what they wanted to make. We used microscale quantities for two important reasons: 1, As a safety precaution The beauty of using the microscale quantities is that ...

Morality: Absolute or Relative?

In the modern study of Ethics one debate has dominated almost all the others, it is the question of whether morals are discovered or invented, in other words whether moral values exist independently of us, whether they are entirely a product of the human mind, or whether there can be a set of moral values universally accepted. In TOK, this is an issue which you will encounter in different forms and in different places. TOK requires us to address the ...

More puzzles

It's sometimes hard to define whether a puzzle can be classified as "mathematical" or not. They certainly are if they require mathematical techniques or knowledge to solve them. Today's puzzles don't, but I would still class them as mathematical: firstly, because they use numbers or geometrical space or logic; and secondly because they tickle the mathematical bits of your brain and so, in a very small way, hone your skills. 1. The two jugs Solve this in under 30 seconds - excellent. ...

Saudi women allowed to drive

Clerics in Saudi Arabia, the birthplace of Islam, have long struggled to justify the kingdom’s decades-old ban on women driving. None could cite a verse in the Koran to justify barring women from driving a vehicle. On September 26th the Kingdom decided to lift the ban. The decision was welcomed by women and many men. It will give Saudi women a freedom that others take for granted. It will have economic benefits, too, sparing families the cost of hiring a (male) ...

The May 2017 Subject Report is now available

Most understandably, there was a small delay in the release of the subject report.  With all new assessments, there was much to report on and the examiners responsibly clearly wanted to provide clarity on the expectations of the assessments, and advice for future candidates.  A lot of work goes into these reports, and in IB history, with nearly 50,000 students writing 10 different exams and completing an internal assessment, there are a lot of variables to consider. (Please note that as of ...