Name: Sodium

Symbol: NA
Atomic Number: 11
Relative Atomic Mass: 22.99
Category: Alkali metal
Appearance: Silver coloured metal

Above: Image © istockphoto.com/3dalia

Sodium is a very important and useful element. It is also one that needs to be treated with care. For example, you need to consume sodium regularly in the form of table salt—sodium chloride (NaCl). But too much salt can lead to serious health problems. Also, sodium in its elemental form (not part of a compound) is very reactive and explosive. It can even explode and cause fires when it’s in water! Because of its reactivity, sodium is never found in its elemental form in nature.

Salt, in the form of NaCl, is mined across Canada. In the Atlantic provinces, it comes from ancient inland seas that have since dried up. The world’s largest salt mine is in Goderich, Ontario. Here, the giant deposits found deep underground are drilled and blasted to break off smaller pieces. Salt mined in this way is not pure. In order to be purified, the salt is dissolved. Then, the water is evaporated. This allows the salt to recrystallize, and any impurities to be washed away.

Did you know? Sodium is found in many common household products, including table salt (sodium chloride), baking soda (sodium bicarbonate), lye (sodium hydroxide), and borax (disodium tetraborate).

There are many uses for sodium-containing salt. For example, it is used as a de-icer for roads in the winter. Salt interferes with the water molecules, making it harder for them to freeze. As a result, ice forms at a much lower temperature. Sodium chloride can actually lower the freezing temperature of water from 0°C to -21°C. However, salt is very corrosive. This means that it damages other materials, especially metals. This is why so many cars begin to rust after years of salt exposure.

All of the cells in your body need sodium. Sodium allows your muscles to contract and your nerve cells to communicate. However, if you get too much sodium, it can be very bad for your health.  Taking in too much salt in your diet can raise the amount of sodium in your blood. The extra sodium in your blood causes your kidneys to work extra hard to pull out water to produce urine. This can cause excess fluid and strain on the blood vessels around the kidney. Over the long term, this can lead to kidney disease or hypertension (high blood pressure). Hypertension can lead to heart attacks and strokes.

Did you know? Sodium is one of the 10 most abundant elements on Earth. It makes up 2.6% of the Earth’s crust.

Adults and children over the age of 13 should only take in 1500-2300 mg of sodium a day. this is less than one teaspoon of salt. However, on average, Canadian males aged 14 to 18 tend to take in more than double this amount: 4000 mg a day! To avoid consuming too much sodium, you should avoid eating too much bread and processed meat, both of which are major sources of sodium for Canadians.

Sodium is a very important component of sodium chloride, the salt we use to flavour our foods and salt our roads. However, due to the health consequences of consuming too much salt and the corrosive action it has on cars, sodium could be too much of a good thing!

Learn more!

Sodium (2015)
UK Royal Society of Chemistry

Sodium: the essentials (2015)
Mark Winter, WebElements

The Element Sodium
Steven Gagnon, Jefferson Lab

Websites providing basic information on sodium.

Periodic Graphics: Deicers And Antifreeze (2015)
Chemical & Engineering News, American Chemical Society

Infographic on different types of deicers, including sodium chloride, and their uses.

Salt in Canada (2014)
Compass Minerals

Brief overview of salt mining in Canada.

Sodium in Canada (2012)
Health Canada

Salt’s effects on your body (2008)
Blood Pressure UK

Websites with information on salt consumption and associated health risks.

A pinch of sodium (2011)
Margit S. Müller, Nature Chemistry 3

Short article discussing the importance of sodium, including its industrial applications and its biological role.

Kelly Resmer

Kelly is a chemistry undergraduate laboratory instructor in Halifax.  She loves working with students in the lab, watching chemistry happen! She has a PhD in chemistry and is very interested in studying and learning about bacteria, the good and the bad ones! 

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  • Does anyone in your family have to limit the amount of salt in their diet?
  • Have you or anyone in your family experienced salt damage to clothing or footwear?
  • It is recommended that adults and children over the age of 13 consume only 1500-2300 mg of sodium a day. Chart you daily salt consumption. Is it more or less than the recommendation?
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