Lessons 8,9 and 10

Starting with lesson 8, we learned about sublimation. Sublimation is the phase change from a solid to a gas. Remembering back to the lab, when we saw the "fog" around the dry ice, it is actually tiny droplets of water. Something important to know is that the gaseous co2 can occupy is dramatically larger than the space that a solid co2 occupies. Moreover! Evaporation (in case you didn't know ;)) is the phase change from a liquid to a gas. An important equation you'll need to know is %error=experimental value-accepted value devised by an accepted value times 100. A fun fact to know closing up lesson 8 is that molecules of gas are about 1000 times more dispersed (less dense) than the molecules of a solid.

Lesson 9 covered air pressure! We watched some demonstrations showing air pressure. For example, if you were to try to blow up a ballon while it was in a bottle, due to the air pressure in the bottle, it is impossible. All the demonstrations were really fascinating! In case you were wondering, air pressure is the force per unit area exerted on objects as a result of gas molecules colliding with those objects. Pressure is similar, but its important to know the definition. Pressure is the force applied over a specific area. Force per unit area. Gas pressure is caused by gas molecules striking objects or the walls of the container. A mixture of gases that surrounds you at all times is called the atmosphere! Along with that come atmospheric pressure which is important. It is air pressure that is always present on earth as a result of air molecules colliding with the surfaces of objects on the planet. Lesson 9 closes up with knowing that at sea level, and 25° C, there is a 14.7 in/in2. This is referred to as 1 atmosphere of pressure or 1 amu.

Lesson 10 covers Boyles law. If you understand that, than lesson 10 is done! Boyles law is the pressure of a given amount of gas is inversely proportional to its volume if the temperature and amount of gas are not changed. When volume of a gas decreases, it's pressure increases. The mathematical relationship between pressure and volume is P=k/V or PV=k.

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