Elements for Kids
- Symbol: Mg
- Atomic Number: 12
- Atomic Weight: 24.305
- Classification: Alkaline earth metal
- Phase at Room Temperature: Solid
- Density: 1.738 grams per cm cubed
- Melting Point: 650°C, 1202°F
- Boiling Point: 1091°C, 1994°F
- Discovered by: Joseph Black in 1755. Isolated by Sir Humphry Davy in 1808.
Magnesium is an alkaline earth metal
and is the second element located in the second row of the periodic table. It is the eighth most abundant element on Earth. Magnesium atoms have 12 electrons and 12 protons. There are two valence electrons in the outer shell.
Characteristics and Properties
In standard conditions magnesium is a light metal with a silvery-white color. When exposed to air, magnesium will tarnish and become protected by a thin layer of oxide.
When coming into contact with water, magnesium will react and produce hydrogen gas. If submerged in water, you will see gas bubbles start to form.
Magnesium burns with a very bright white light. At one time magnesium powder was used to produce a bright flash for photography.
Where is magnesium found on Earth?
Magnesium is fairly abundant on Earth in compounds and is found in over 60 different minerals in the Earth's crust. Some of the most important minerals include dolomite, magnesite, talc, and carnallite. The compound magnesium oxide (MgO) is the second most abundant compound in the Earth's crust making up around 35% of the crust by weight.
A significant amount of Magnesium is also found dissolved in ocean water. In ocean water it takes the form of the cation Mg2+
. A lot of commercial magnesium used in the United States comes from a process using electrolysis to extract it from sea water.
How is magnesium used today?
One of the main uses of magnesium metal is in metal alloys. This is because it is both strong and light. It is often mixed with aluminum, zinc, manganese, silicon, and copper to make strong and light alloys for use as automobile parts, aircraft components, and missiles.
Magnesium metal is also used in electronic components. Its light weight and good electrical properties make it a good element for use in cameras, mobile phones, laptop computers, and other handheld electronic components.
Another application of magnesium is in various compounds. Some compounds are used as medicines such as magnesium hydroxide which used to help indigestion (Milk of Magnesia) and magnesium sulfate (Epsom salts) which is used in baths to soothe sore muscles.
The human body needs magnesium for good health. It is used to make proteins, strong bones, and to regulate the body's temperature.
How was it discovered?
Scottish chemist Joseph Black first demonstrated in 1755 that the substance magnesia alba was a compound of different elements, one of them being magnesium. The element was first isolated by English chemist Sir Humphry Davy in 1808.
Where did magnesium get its name?
Magnesium gets its name from the district of Magnesia in Greece
where the compound magnesium carbonate was first found.
Magnesium has three stable isotopes including magnesium-24, magnesium-25, and magnesium-26.
Interesting Facts about Magnesium
More on the Elements and the Periodic Table
More Chemistry Subjects
- For many years magnesium was thought to be the same element as calcium.
- A magnesium fire is very difficult to put out as it can burn in nitrogen, carbon dioxide, and water.
- It is used in flares and fireworks because of its bright white light when it burns.
- If you pour water on a magnesium fire, it will only make the fire worse.
- Magnesium is sometimes used to help shorten the length of migraine headaches.