Sodium

A few weeks ago I started making dinner and turned on the television to watch the news but forgot to change the channel. The show “Are You Smarter Than a 5th Grader” came on, which I have to admit I’d heard about but never watched. I decided to listen as I cooked just to see how I did. One of the questions was, which element on the periodic table is known by the symbol Na. I was so excited – I actually knew the answer. Even better, the gal playing the game missed it! It was a small triumph though because she pretty much got all of the other questions correct and I – did not. Apparently, I should be watching that show and not the news.

Symbol: Na / Group: Alkali Metal / Atomic Number: 11

Sodium is most commonly known to us as salt. But our table salt is not pure sodium, it’s actually sodium chloride (NaCl), which is the combination of the elements sodium and chlorine. And if we happen to be on a low-sodium diet, then it’s potassium chloride we are eating. Potassium chloride isn’t as tasty as sodium chloride and has a bitter metallic note to its saltiness, which must be why people prefer regular salt.

When exposed to air, the silvery color of sodium tarnishes, turning white within seconds. What is most interesting about sodium is that it’s extremely explosive. When you throw sodium into water, it rapidly generates hydrogen gas and seconds later ignites with a massive bang spewing flaming sodium in all directions. The other alkali metals react in much the same way, but when sodium reacts with water it produces sodium hydroxide, or Lye which is commonly used as a drain opener.

The salt in our oceans isn’t pure sodium either. It’s mostly sodium, chloride, magnesium, calcium, potassium and sulfate. The elements of this salt “cocktail” arrive from various sources: decayed biological matter, volcanic vents in the Earth’s crust, breaking up of rocks via erosion of mountains, the dissolving action of rain, streams washing particles into the oceans, and even from our atmosphere. This complex salt content of our oceans is why sea salt tastes different from our typical table salt. The elements that make up both are not the same.

So why is the symbol for sodium Na and not So? Sodium comes from the Latin name natrium, which actually comes from the Egyptian name natron, the word for the natural mineral salt.

Now you’re a little smarter, Girlfriend — And so am I.

The Periodic Table

Not sure why, but I'm fascinated by atoms, elements and how the periodic table works. I totally did not get it in chemistry class in high school and college, but now it makes (more) sense. Although the details of each are very complex. For instance, Hydrogen is one of the most volatile elements, but mix two Hydrogens with Oxygen and it's extraordinarily neutral and gives us water.

Everything in the universe is made of elements. An element is a substance that cannot be broken down or made into anything simpler by chemical reactions. Several elements, like gold, silver and lead, have been known for thousands of years. Darmstadtium, on the other hand, was created in a lab in the 1990's.

Siberian chemist Dimitri Mendeleev arranged the elements into the periodic table in 1869. He organized them in groups (columns) and periods (rows) leaving gaps for elements that were still undiscovered. Today, those gaps have been filled to a total of 118 known elements but certainly there may be others that have yet to be discovered.

The vertical groups of the table make up "families" that are closely related and liking the same types of chemical characteristics. Mendeleev organized the elements so that each had a higher atomic weight than the one on its left and by similar chemical properties to other elements in the same column.

In 1913 Henry Moseley discovered it was the atomic number (charge) and not the atomic weight that is most fundamental to the chemical properties of any element. The element's chemistry is determined by the way its electrons are arranged.

There is a progression from metals to non-metals across each period. The block of elements in groups 3-12 contain the transition metals. The rare Earth elements are groups 58-71 (lanthanides–chemically similar to each other) and 90-103 (actinides-less chemically similar to each other). Naturally occurring rare Earth elements are found only in very small amounts. The actinides include most well known elements that take part in or produce nuclear reactions. No element with an atomic number higher than 92 occurs naturally and are produced in nuclear reactors or particle accelerators.

In researching the periodic table, I found conflicting information regarding how many elements were on the periodic table and even how some of them are grouped. But for the most part, it looks like there are 118.

Now you’re a little smarter, Girlfriend — And so am I.