Middle and High School … from a Montessori Point of View
Covalent bonding happens when atoms share electrons, unlike with ionic bonding where one atom gives electrons to another. Why do some combinations of atoms make ionic bonds and others covalent bonds? The answer has to do with electronegativity, which is the ability of atoms to attract electrons to themselves. Atoms that have similar abilities to … Continue reading “Introducing Covalent Bonding”
Now that we’ve learned how to draw individual atoms (and have an online reference for the first 20 elements), let’s consider ionic bonding. The key thing to remember is that atoms all “want” to have their outer electron shells filled. So while a sodium (symbol: Na) atom is happy* enough that it has the same … Continue reading “An Introduction to Ionic Bonding”
Why is the periodic table called the periodic table? Because of the periodic changes in the properties of the elements: there are patterns to the properties that repeat, time after time, as you go through the sequence of the elements. One key repetition, which affects the way different elements react, is in the electron configurations, … Continue reading “Patterns in the Periodic Table”
Having demonstrated how to draw a few simple atoms, I had students fill out a periodic table template with drawings of the first twenty atoms. Actually, I only had them draw the electrons in their shells because it reduced the messiness of trying to fit in forty nuclear particles into a small tile, and the … Continue reading “Electron Configurations on the Periodic Table”
Our middle-school dissections have moved on from hearts to whole organisms. This week: jumbo shrimp. I particularly like these decapods because the external anatomy is simple but interesting, including: eyes on stalks; a segmented body; 5 pairs of swimming legs; 5 pairs of walking legs. The simple, clear layout make them a good subject for … Continue reading “Shrimp”
Elements can be identified from the color of light they give off when they’re ionized: their emission spectra. Ms. Wilson’s chemistry class today set fire to some metal salts to watch them burn. She placed the salt crystals into petri dishes, submerged them in a shallow layer of alcohol, and ignited the alcohol. As traces … Continue reading “Flame Tests”
A quick and simple experiment that demonstrates endothermic reaction and can include a discussion of ionic and covalent bonds. Mixing baking soda and vinegar together drops the temperature of the liquid by about 4 °C in one minute. (Note that while the temperature drops and the reaction looks endothermic, it’s actually not — other things … Continue reading “Endothermic Reactions: Vinegar and Baking Soda”
Another, excellent example showing the scale of the universe (only goes the size of the hydrogen atom though: this one goes a bit deeper). The Universe made possible by Number Sleuth