Magnesium - Atomic Number 12
Magnesium – Atomic Number 12

What better element for Super Bowl week on my Periodic Table of Photography than Magnesium (Mg – Atomic Number 12). Go Seahawks!

Magnesium is at the other end of the density scale from the last element I featured – Tungsten – and is only 2/3 the density of Aluminium.  Alloys of Magnesium and Aluminium are used where weight (or lack of it) are important.  Cars, planes, luggage, laptop shells and also camera bodies.  So a key modern photography use – as well as a very old photography use – flash powder – as it ignites easily in air and burns with a very bright light.  Later, flash bulbs, or the flash cubes on Kodak Instamatics used Magnesium ribbon – ignited by an electrical charge. This property also led to its use in flares, sparklers and other fireworks.

This was New Years Eve a couple of years ago – but hopefully the fireworks will be loud this Sunday too!

NYE - Space Needle
NYE – Space Needle

Magnesium is also a very important element biologically, being the seventh most abundant element by mass in the body and integral to the working of many human enzymes.  In plants it is at the heart of chlorophyll – critical to photosynthesis and which leads to Oxygen production in green plants.

Magnesium is found in minerals such as magnesite and dolomite, but industrial production makes use of its abundance in sea water.  It was named after a district in Greece – Magnesia – where is was found along with similarly named Magnetite (an iron oxide) and Manganese (an element – Mn).

Magnesium Alloy wheels
Magnesium Alloy wheels

An experiment that I always remember from school was the thermite experiment – where Magnesium ribbon is used as a fuse to start the exothermic reaction of a mixture of an oxide and a metal – usually in chemistry lessons Iron Oxide and Aluminium – which then produces molten Iron and Aluminium Oxide. In our class this was done in a clay flower pot and the molten Iron stream out of the bottom…

Mag wheels became a common term for lightweight alloy wheels on cars – and these may or may not really be Magnesium or a Magnesium alloy – but the name stuck.

Epsom salts (hydrated Magnesium Sulphate) were originally discovered by a farmer in Epsom, England in 1618 – who noticed that his cows would not drink water from a particular well as it had a bitter taste.  The farmer noticed however that the water helped scratches and rashes to heal – and its fame spread. Another medicinal use of Magnesium salts is as an antacid (Magnesium Hydroxide) – such as Milk of Magnesia.

Following Magnesium I have another light weight metal – as I spell out AlIce – with Aluminium, Iodine and Cerium.

NYE Space Needle, Seattle
NYE Space Needle, Seattle