How To Teach Science During Breakfast… With Coffee
My breakfast table would not be complete without a steaming cup of coffee.
It is true that I have a deep love for bacon, but I could easily pass up this fried goodness for my morning coffee. People who know me well would say my zombie-like appearance will not change at all without this “medicine.”
Now I’m not going to give you too much science to chew on this morning. Like all of the posts in this series, I am only going to focus on four main concepts to describe the science of my breakfast beverage:
For those of you out there who do not share this same passion, you can substitute your favorite hot drink of choice. I won’t think any differently of you…
So what is happening to the atoms of water while they are boiling?
This is an easy one! The water molecules (a group of two Hydrogen atoms and one Oxygen atom) are absorbing all of that heat from the stove and bouncing around faster and faster until they break loose from each other and form a gas (also known as water vapor.) Remember, the more energy an atom can absorb, the faster it moves away from other atoms.
Up next, our good friend Mr. Diffusion…
If you are using a tea kettle, you know exactly when all these molecules start to break loose. These energized groups of atoms start bouncing around inside that kettle until they find a way to escape – through the whistle! You could say that all of these atoms are diffusing from the kettle into the air!
As millions of water molecules are forced out of this tiny whistle, the tea kettle begins to play its tune, telling us it’s time to make coffee.
Why is water vapor forced out of the kettle so quickly?
I could spend dozens of pages to answer this question, but I only have four concepts to cover today. The density of the water vapor is much higher inside the tea kettle than in the air surrounding the kettle. This means there are more molecules of water vapor bouncing around inside that kettle than there are just outside of the kettle.
So, the larger group of high-energy atoms inside the kettle diffuses into the surrounding air.
I can’t see the water vapor after it leaves the tea kettle anymore. Did they disappear?
Nope! The number of atoms within the liquid water molecules never disappears. They only absorb energy from the stove, break free from each other, start bouncing around inside the kettle, and escape into the air. The Law of Conservation explains why this happens – Atoms cannot be created or destroyed, only rearranged.
All of those atoms that are whistling at us may still be floating around in our house day after day after day. Or, perhaps some of them have slowed down a little bit and turned back into liquid water. Who knows? All we can be certain of is that no atoms were destroyed during the entire process.
This Law can be used to explain another concept related to coffee – the grinding of the coffee beans.
If you were to weigh a single coffee bean before and after crushing it into a powder, what would happen to its weight? If you said “Nothing” you would be correct. If you were to weigh all of those little pieces of coffee bean and add them up, it would equal the same weight as the whole bean. Why?
Because the atoms within the bean cannot be created or destroyed, only rearranged.
Do you like your coffee strong (like me) or weak?
Adding more ground coffee places more atoms into the coffee. So, this means that you increase the density of the coffee by adding more atoms into the brew.
Do you add milk or sugar to your coffee?
Whatever you add to your coffee doesn’t just sit there, floating on the top of your cup, does it? I hope not! The atoms within your milk or sugar tend to diffuse throughout the coffee when they mix together. The large amount of atoms within the milk spread throughout the atoms of the coffee. The same happens with the sugar. If your sugar didn’t diffuse through the coffee, it may taste sweet on the first sip, bitter the next, and back to sweet on the third sip. This doesn’t happen because the atoms of sugar diffuse evenly (almost) throughout the coffee.
Never forget – You do not need a lot of expensive equipment to teach science. You only need the right tools…
Atoms, Diffusion, Density, and the Law of Conservation…
…and a good strong cup of coffee!
Find out more about these and many more scientific concepts within the Classic Science Curriculum.
