On this page: Properties of Water | Solution & Crystallization | Mixtures & Separation | Experiments

properties of water

▶️ How polarity makes water behave strangely from TED-Ed. “Water is both essential and unique. Many of its particular qualities stem from the fact that it consists of two hydrogen atoms and one oxygen, therefore creating an unequal sharing of electrons. From fish in frozen lakes to ice floating on water, Christina Kleinberg describes the effects of polarity.” – Middle • High

▶️ Why don’t oil and water mix? from TED-Ed. “Salt dissolves in water; oil does not. But why? You can think of that glass of water as a big, bumpin' dance party where the water molecules are always switching dance partners, and they'd much rather dance with a salt ion. John Pollard explains how two chemistry principles, energetics and entropy, rule the dance floor.” – Middle • High

▶️ Why does ice float in water? from TED-Ed. “Water is a special substance for several reasons, and you may have noticed an important one right in your cold drink: ice. Solid ice floats in liquid water, which isn't true for most substances. But why? George Zaidan and Charles Morton explain the science behind how how hydrogen bonds keep the ice in your glass (and the polar ice caps) afloat.” – Middle • High

solution & crystallization

✏️ Concentration from PhET. “Watch your solution change color as you mix chemicals with water. Then check molarity with the concentration meter. What are all the ways you can change the concentration of your solution? Switch solutes to compare different chemicals and find out how concentrated you can go before you hit saturation!” – All

mixtures & separation

▶️ The science of macaroni salad: What’s in a mixture? from TED-Ed. “What’s in macaroni salad? Break down the pasta, mayonnaise, vinegar, mustard, vegetables, etc., and you’re left with a bunch of molecules. Josh Kurz uses a delicious recipe to exemplify three types of mixtures (solution, colloid and suspension), while reminding us that we’re all made of the same stuff.” – All

▶️ How do we separate the seemingly inseparable? from TED-Ed. “Your cell phone is mainly made of plastics and metals. It’s easy to appreciate the process by which those elements add up to something so useful. But there’s another story we don’t hear about—how did we get our raw ingredients in the first place, from the chaotic tangle of materials that is nature? Iddo Magen uncovers the answer in a group of clever hacks known as separation techniques.” – Middle • High

experiments