Learn about Junior Chemistry, The Periodic Table 1, in this comprehensive video by bannanaiscool.
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Rob Lederer: So what do we got here? Well, we actually have two elements in their natural state. These are kind of special because, you don't see these normally anywhere on the planet. Here is the piece of sodium and here is another group one element from the periodic table, lithium. I will show you where those positions are on the periodic table in just a moment. But here is two metals and what happens actually when you cause a reaction with a little piece of lithium that I have chipped off of here, actually just using the scupula because, lithium and sodium are very, very soft metals. Well, I can actually create a chemical reaction here by just putting these metals, metals into water. This is just water. Look at that lithium go reacting in that water. So, how about a piece of sodium? Sodium goes into the water. The reaction is far more vigorous. Chemistry is the study of stuff. That's part of it. But let's make it fancy term and call stuff matters. So, chemistry is the study of matter, of all the material things in our universe. Now, there is a lots of different ways to categorize or group this type of material, right? There are certain types of mixtures that look pretty much the same all the way through. We call those homogeneous mixtures, but some of those like if you put marbles into water. Well, that's a mixture, but it is a heterogeneous mixture. You can still see the individual properties of the things that are involved in the mixture. Well, whether you got homo or heterogeneous types of mixtures, everything can be kind of turned into and broken down into substances. So, we can actually take that divide it into pure substances. Pure substances can be further be broken down into to the compounds and into the ionic compounds or molecules that make up the substance. Okay and then when we take these compounds or molecules. Now, we break them down even further and we get to the essence, where we arrive at a substance that cannot be, by chemical or physical means, broken down to simpler substances that it really exists on their own. Now, we are talking about elements. And elements, those are the things that make up this wonderful chart in behind me here called the periodic table. Now about a 150 years ago, there wasn't really a scheme or a chart system in order to organize all of these elements and it came to two scientists of that time, one was named Lothar Meyer, he is a German and Dmitri Mendeleev, a Russian kind of working independently, but almost at the same time produced this that you see behind me, the periodic table. Credited to Mendeleev for his fine work. Now, the periodic table is, well doesn't look like a very nice kind of table or chart. You think that may be things could have been condensed and kind of squared off and no, no, no. this thing here, it's so beautiful. It's brilliant in its execution because, what it does is that it organizes the elements, these things that can't be broken down by chemical or physical needs into simpler substances that naturally occur. It organizes them in terms of increasing atomic number and that's the number of protons in the nucleus. We will get about just a second. And it also groups them in terms of similar characteristics or properties going down. That's how Mendeleev organized his table, in terms of similar chemical characteristics. So, we look at the periodic the table and we start with the far left hand side. by the way, it is called periodic because, there are trends that occur periodically going down and also remember that we read everything in terms of atomic number from left to right and you know sentences we read here in North America from left to right may end in a period. So, remember the periods go across, and the groups go down. And here is first group on the periodic table. Some of them have common names. You got to know them. Lithium, sodium, potassium, Rubidium, Cesium and Francium here in group 1A or Group 1 of the periodic table and hydrogen is includ