Matter and Properties
In accelerated chemistry we started of the year by gaining/refreshing some basic knowledge on matter and it's properties. Some of the terms we covered were: system, surroundings and mass. One main topic which I felt the week lead to was the Law of Conservation of Mass. Something that I believe messes most people up is the fact that spreading the molecules out in an object doesn't change it's mass. For example. stretching out steel wool didn't change the weight, it just took up more space.Mass cannot be created nor destroyed.
Physical Change VS Chemical Change
Another lesson which I thought was important was the difference between a physical and chemical change. In my opinion one of the hardest things to differentiate for the average person is whether and object changed physically or chemically into a new object. Most of the labs we did pertained to using heat, acidic and basic chemicals, and creating solutions or changing states of matter. For example, melting ice. Changing from a solid to liquid is just a physical change. But, a large discussion was related to expansion of molecules with heat because water is the opposite of most substances.
Volume
The last concept we cover was volume. In the lab we calculated the volume of a container by measuring it. Then we filled it with water and found the volume. At the end we compared cm cubed to ml. In our discussion we talked about inconsistencies and inaccuracies. Such as thickness of plastic, curved edges, and "misplaced" water. Knowing that a cm. cubed is the same as a ml is helpful in my opinion.Thoughts
I think that everything we learned this past week will be helpful for the rest of the year. A lot of topics are more of a review or refresher than new material so far. But that was expected. The only question or want you could say, that I have would be a list of aspects for both chemical and physical changes. We got pretty good at diagnosing the two but a clear cut list wouldn't hurt me.
Evan Sebranek,
Period 8 Accelerated Chemistry
