Question: How do you know what the materials are made up off?

Martin Wieczysty answered on 20 Mar 2015:

Very good question – and very important in chemistry. In my job, I sometimes make things by accident. I would like to know what they were – what the materials were made up of. I would take a sample a use a variety of machines, and from the results I can understand what the material is made up of:

Spectroscopy: This is a fancy term for what colour is the material. Remember there are some colours we cannot see, we call them infra-red (given of when something is heated) and Ultra Violet (like the rays of the sun).

Mass Spectroscopy – this “weighs” the molecules in the material,

Melting point: What temperature does the material melt at

X-ray Crytalography: If I am lucky to grow a crystal of the material, I could fire X-rays at it, the X-rays bend around the molecule, and using a computer program, the structure and chemical formula of the molecules which make up the material can be found.

Chromatography: If you were to take a strip of paper, and mark a line width ways about 2 cm from the bottom, then dip it in a jar of water about 1 cm deep, the water would rise up, and the ink would separate into different colours. This is because (sometimes) there are many coloured components that make up a dye. – This is chromatography.
I use a more fancy machine to do this, that can separate out mixtures within the material. Where it separates can give an indication of what the material is.