Continuing from an earlier post (if you haven’t read the earlier post, it can be found here)
Part 2: The Whole is More Than the Sum of the Parts
So in the last post, I used Sodium Chloride (NaCl) in an example of scare tactics. Some of the features of the elements sodium and chlorine (chloride) are pretty scary, but the compound sodium chloride is edible and fairly harmless. So why is that? Why are the elements scary but the compound isn’t?
This has a lot to do with chemistry, as I hinted at in the last post. In general, chemistry is the science of how the little charged particles orbiting atoms (called electrons) move around. As these particles move around, energy is released in the form of heat and/or light. The science of chemistry has found that the movements of electrons follow predictable patterns, and that in general these electrons try to move from high energy states to low energy states, releasing energy in this process. This will be the general model that we will use in all of our discussions, and it is about as deep into chemistry as we need to go for basic discussions.
A great example of such a chemical reaction is how a natural gas-fired range works. We have natural gas piped into the range, and the gas burns to cook food. The gas breaks down into carbon dioxide molecules (CO2), and CO2 has its electrons in a lower energy state than they were in the natural gas. The fire (heat + light) is what the electrons give off as they move into this new, lower energy configuration. If we were to put this in an equation type-format, it would look like this:
Natural Gas In –> CO2 + Light + Heat
What we find when looking at the periodic table is that many elements have electrons that are in high energy states. Two good examples of such elements are those that we discussed earlier, sodium and chlorine. Both as elements have electrons in very high energy states, and those electrons are constantly looking for ways to get down to a lower energy state, and they will release light and heat in that process. It is this constant looking for a way to get to lower energy that cause sodium and chlorine to engage in nasty, violent, scary reactions. See below for a link to a video of sodium added to water — pretty scary right?!!!!!!!!!!!!!
Video 1 — courtesy of ScienceFix on YouTube. Please check out all of their awesome content.
Going back to our original question, if sodium reacts so violently, why can we ingest it in the form of table salt? We can ask a similar question about chlorine. The reason is this: the elements sodium and chlorine actually do react quite violently together to form the compound sodium chloride. What happens here is that 1 electron from sodium moves over to chlorine, and that electron gives off heat and light in that process. Once the electron has completed its movement, the compound sodium chloride is formed. The reason sodium chloride is a safe, stable compound is that the electron movement has already happened — sodium chloride is what is left over after the reaction is done! For an interesting video of a sodium-chlorine reaction, see below. The presenter does a fantastic job, and his discussion topics fit in well with what we are discussing here.
Video 2 — courtesy of NileRed on YouTube. Please check out all of their awesome content.
So that take-home point is this, yes sodium + chlorine = very violent reaction. But once that reaction is done, we are left with a stable, nice compound that we can eat — table salt! The electrons have already done their moving, so there is no more electron movement to be done. Thus, there is no more heat + light to give off. So sodium + chlorine is very violent, but once the violent reaction is over, a new stable compound (sodium chloride) is formed.
In summary, the elements that have electrons capable of moving and thus giving off heat and light are scary, but once that movement is done, the scariness is gone. In the following articles, we will continue to explore this concept. This is the concept at the heart of why the elements making up a compound can be scary, but he compound can be perfectly safe. Also, if you are interested, below is another video about the sodium + water reaction by Thunderf00t. Thunderf00t posts fantastic content on YouTube, and I highly recommend checking out his content.
Video 3 — More detailed look at the sodium + water explosion on YouTube by Thunderf00t. Please check out all of his awesome content.
Sources:
Video 1 — courtesy of ScienceFix on YouTube. Please check out all of their awesome content.
Video 2 — courtesy of NileRed on YouTube. Please check out all of their awesome content.
Video 3 — More detailed look at the sodium + water explosion on YouTube by Thunderf00t.