We use different types of metal every single day, from the frame of our cars to the silverware we typically use to eat lunch. Many of these metals fall into different families on the periodic table. Today, we’ll be talking about alkaline earth metals. What are alkaline earth metals, and where might you encounter them in your daily life?
Properties of the Alkaline Earth Metals
First, what are alkaline earth metals?
Late in the 18th century, any substance that could not be dissolved in water and did not burn or melt in regular fire was referred to as an ‘earth.’ From there, they were classified by their resemblance to other known materials. Alkaline earth metals had a striking resemblance to other known alkalis, such as soda ash or potash, so they were classified as such.
Later, it was discovered that the elements being classified as alkaline earth metals were actually oxides of those metals — the metal atoms were combining with oxygen.
The alkaline earth metals, in order of abundance, are:
Calcium is the fifth most abundant element in the Earth’s crust, coming in behind magnesium, silicon, iron, and aluminum.
Physical and Chemical Properties of Alkaline Earth Metals
What sets alkaline earth metals apart from other metals on the periodic table?
First, though classified as metals, these elements are fairly soft and malleable. They have lower melting and boiling points than other metals but are still strong when compared to other, similar elements. The earth metals are also highly reactive in their pure state, which is why they are not usually found in this state in nature.
These earth metals also burn in a variety of different colors. Calcium and radium both burn red, while beryllium and magnesium burn white and barium burns a bright green.
In the future, if element 120 is added to the periodic table, it will most likely be a new form of alkaline earth metal.
What Will Scientists Discover Next?
Science news delivered weekly!
Where do you think you encounter alkaline earth metals in daily life? The answer might surprise you. We’ll start with the most abundant element — calcium.
Calcium is important for strong bones and teeth in the human body. It appears in milk and other dairy products and has been added to a number of food types so everyone gets enough of it in their daily diet. It appears in toothpaste and some vitamins, supplements and even antacids in the form of calcium carbonate. On the industrial side of things, it’s used to make materials like slaked lime for use in producing glass and paper.
Magnesium is another element found in food, and it’s important for a healthy body. It appears in foods like nuts, spinach, black beans and tofu. If you’ve ever driven a car or ridden in an airplane, you’ve probably encountered the metal version of magnesium — when tempered and mixed with zinc and aluminum, it can be used to make airplane parts and even car engines.
Barium isn’t an element you’ll usually encounter unless you’ve got a stomach problem. It’s used in medical procedures as a substance that you swallow. It travels through the stomach and intestines and makes these parts stand out in an x-ray or MRI scan so it’s easier for doctors to diagnose problems.
Strontium is one element that you might only encounter on the fourth of July — the fact that it burns bright red makes it a perfect additive for fireworks. If you’ve seen a rocket’s red glare, you probably saw strontium.
Beryllium is one element you won’t encounter in its pure form, primarily because it’s combined with other metals to make alloys for tools. It helps make the base metal stronger and more stable at higher temperatures. In flammable environments, tools made of a copper-beryllium alloy are used to prevent sparks that could cause a fire or explosion.
Radium doesn’t have many, if any, industrial applications, so you might not encounter this element in your daily life. This lack isn’t a bad thing — radium is produced by the decay of uranium, which makes it highly radioactive. It was discovered by Marie Curie and may have been one of the elements that contributed to her death from radiation poisoning. Before its radioactivity was detected, it was used for luminous paint and on watch dials.
Where have you encountered alkaline earth metals in your daily life? Hopefully, radium wasn’t one of the ones you encountered, but many of the others help to subtly shape our lives in ways that most of us don’t even think about. The next time you hop on a flight, think about the magnesium in the airplane parts or the calcium in the glass of milk the flight attendant hands you. Alkaline earth metals are all around us — you just have to know where to look.