The Kilogram
This Catalyst article looks at the changing definition of the kilogram, a unit of mass and a base unit in the SI system (the International System of units). It has been found that the International Prototype Kilogram (IPK), made in 1879 and kept in a vault in Paris, has lost about 50microgrammes of mass over the years. This may…
Food Webs Uncoupled
A Catalyst article about food chains and food webs. The article studies evidence for global climate change and considers possible causes. It also explores how climate change might affect the food web, with evidence from a long-term study which started in 1931. This article is from Catalyst: GCSE Science Review 2005, Volume 15,…
Dr Gillian Lockwood
A Catalyst article about the working life of Dr Gillian Lockwood, a reproductive biologist who specialises in IVF. The article looks at the ethical issues surrounding fertility treatments for problems such as polycystic ovary syndrome. This article is from Catalyst: GCSE Science Review 2007, Volume 17, Issue 4. Catalyst is…
Catalysts
A Catalyst article about how catalysts affect the rate of reactions and why catalysts are important in nature and in industry. This article is from Catalyst: Secondary Science Review 2008, Volume 18, Issue 3. Catalyst is a science magazine for students aged 14-19 years. Annual subscriptions to print copies of the magazine can…