Mastery Check #2 - Properties of Substances
FOR THIS MASTERY CHECK, IT IS VITAL THAT YOU HAVE COMPLETED YOUR SUBSTANCE POSTER!!!
Why do we choose the materials we use for various functions and why not use a different material? It is important for you to understand that we use materials that are best suited for a purpose because of their unique properties. Below are several examples of unique properties that make things useful for a certain purpose. Diamonds It may surprise you to learn that of all of the diamonds mined out of Earth, roughly only 20% are used in jewelry. So where do the other 80% go and why? The other 80% are used for drill bits and abrasive materials like the examples in Pictures #1 & #2. But we don't use them for drill bits because they are rare and beautiful. Diamonds have a very unique property that make them the very best choice for drilling and cutting- their hardness. Hardness refers to a substances resistance to being scratched. On the MOHS hardness scale (Picture #3), diamonds take their place as a 10 which means that nothing but a diamond can scratch a diamond. This unique property of diamonds makes them extremely qualified to cut through any material humans can put in front of it. Additionally, diamonds are non-reactive when exposed to almost every substance known. This means that they will not dissolve or tarnish when exposed to various substances. This further enables them to be the ideal choice when durability is needed. Make sure to watch the video to the right so you can see how useful diamonds have become for drilling, cutting, and more. |
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Helium
Watch the video to learn about the helium shortage that has been going on for some time. Helium has some very unique properties that make it the best choice for many applications. Of course for balloons, we use helium because of its low density which makes balloons float. But did you know that hydrogen is even less dense than helium? That means that it would make balloons float even better than helium. Additionally, hydrogen is much more abundant and easier to obtain than helium, so why do we insist on using helium? Perhaps the best answer to this question is the 1937 Hindenburg disaster. Watch the video to the right and see if you can figure out why we use helium instead of hydrogen in balloons and other lighter than air craft. Use the internet to learn why if you can't figure it out. |
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The moral of the story is that we choose materials that are best suited for our purposes because of their unique properties. Do some research on the internet to learn what unique properties make the following materials useful for their designated function.
Why do we use gold for jewelry?
Why do we use copper for electronics?
Why do we use boron nitride for locks?
Why do we use steel for bridges?
Why do we use rubber in tires?
Why do we use wood for baseball bats?
Why do we use gasoline for energy?
Why do we use gold for jewelry?
Why do we use copper for electronics?
Why do we use boron nitride for locks?
Why do we use steel for bridges?
Why do we use rubber in tires?
Why do we use wood for baseball bats?
Why do we use gasoline for energy?