How can I use meteorites in chemistry lessons?
Meteorites show elements and compounds in nature: iron-nickel alloys, silicates, sulfides and even organic molecules, and they link to the origin of the elements.
Meteorites can bring life to several chemistry topics.
Elements, mixtures and compounds. Iron meteorites are a natural alloy of iron and nickel, a mixture of metals rather than a compound. Troilite is a compound, iron sulfide, FeS. Olivine is a compound of magnesium, iron, silicon and oxygen. Pupils can sort meteorite components into elements, compounds and mixtures.
The periodic table. CI chondrites have nearly the same proportions of most non-gaseous elements as the Sun, so they represent the raw material of the Solar System. Comparing their composition with Earth's crust shows how planets have separated elements, for example concentrating iron in cores.
Reactivity and corrosion. Iron meteorites rust on Earth because iron reacts with oxygen and water. Chloride from soil speeds this up. This is a real-world example of corrosion and why storage with drying agents prevents it.
Isotopes and atomic structure. Isotopes of oxygen distinguish meteorites from different bodies, and radioactive isotopes date them. Pupils can explore protons, neutrons and isotopes using meteorite examples.
Organic chemistry. Some carbonaceous chondrites contain amino acids, hydrocarbons and other organic molecules. Samples from Ryugu and Bennu contain them too. This links to discussions of the origins of life.
Analytical techniques. Mass spectrometry, chromatography and spectroscopy are all used on meteorites. A short case study of how scientists showed that a meteorite came from Mars can illustrate how chemistry provides evidence.