All right guys, welcome to the very first lecture of CHEM 115, Section 2 for Fall of 2020. I will try to keep these as organized as possible on YouTube and on OnCourse so that you guys can follow along, keep everything straight. This first one's just going to be a lot of background definition stuff, there won't be any problems, so it shouldn't be too big of a deal. So... Basically, we need to define what is chemistry. So, chemistry is the study of matter.
The inherent problem with that is, well, that's a huge topic. So, the study of matter can mean anything from understanding how fossil fuels burn and what's the most efficient way to run them in your car. to environmental problems, you know, like how do the cells in trees in Brazil process certain chemicals, to how food works, to how medicine works. to how the underlying structure of biology works, to how geology works. It's a huge, huge topic.
So one of the inherent problems we're going to encounter with Chem 1 is that pretty much every chapter we're almost going to start a new topic. They are all related, and getting to the end of Chem, if you get through Chem 1 and Chem 2, you will have a broad knowledge of how chemistry works. But unfortunately, it does mean kind of switching topics. a lot.
Okay, so one of the first things we're going to talk about is the scientific method, and I am fully aware that if you've had even up to high school science classes, you've probably covered this about 15 different ways. I am going to go through my interpretation of the scientific method, mostly because I think it gives some perspective as to how to interpret things correctly, and in this day and age of misinformation. debating science, this is probably worth mentioning. So, the scientific method, the way I visualize it, is usually it starts out with some sort of observation.
Okay, there are a couple different types of observations. There are qualitative, These are things like color and size and etc. I typically visualize these as the observations that like a six-year-old would make. Or if I say, if you know, if you ask somebody on the street like, describe this shirt that I'm wearing. They might say, oh it's green or it's blue or it's big or it's soft or it's heavy.
Okay, qualitative. Okay, and those are important. They're just not the only option available. Okay. The other option is quantitative.
Quantitative we are going to do a lot more with in this class. Doesn't mean the other one is not important, it's just not the one we're going to spend the most time on. This is basically anything where we make measurements.
I'm trying a new rig here. So we're going to spend a lot of time, especially in this first chapter, learning how to deal with quantitative measurements. So anyway, you have some sort of observation.
A lot of times people walking down the street do not think really hard about what's happening around them. They just take it for granted. No big deal.
They just let it happen. So a scientist or a chemist would see something and be like, wow, that's weird. I wonder how that works.
And then the idea is it leads to a hypothesis. Okay, now a hypothesis is essentially just an untested best guess, okay? It's literally just your best guess. Okay, and then...
The scientific method is essentially just unchecked curiosity. So a scientist or a chemist or a biologist or a geologist or whatever, a physicist, will be like, oh wow, that's weird, I wonder how that works, and then they'll come up with the best guess, and then they'll develop experiments to test it. Okay, and then the experiments are something that can be replicated, something that has controlled conditions, something where specific things are being measured.
And then the idea is this leads to new observations. And the cycle repeats. So essentially leading to new observations brings us back up here.
Okay, so the idea is as you continually make observations, you can adjust your hypothesis. And you keep getting new observations, which leads to new experiments, and it's a cyclical thing. And essentially what you get is if you thoroughly test this, you end up with a theory. So this is a thoroughly tested hypothesis. A hypothesis.
And the understanding is that basically this allows us to make predictions. Okay. This does not mean that we have all the answers.
It does not mean that everything that we are studying is completely understood and perfect. It's just a working hypothesis that has been tested thoroughly. So, for example, gravity is a concept that we have understood for years.
We understand how planets move because of gravity. We understand how your car is going to go up. a hill because of gravity or is going to have to struggle to get up a hill because of gravity. We understand how a tree is gonna fall.
We understand how, you know, if we shoot a rocket it's gonna, or a missile, it's going to shoot in a certain trajectory because of, and gravity is going to affect that. But at the fundamental, at the sub-atomic level, we do not understand what pulls materials towards themselves. Okay, so really the nuts and bolts of it, we don't actually understand how it works.
There's lots and lots of hypotheses out there that are being tested right now, and people think they've got working theories, but there's still some holes to it. The idea, of course, is that basically, I don't actually care. The scientific method for me means that I don't actually have to know those bits. For me, all I need to know is that if I jump off the roof, I'm probably going to break my legs. So the thoroughly tested hypothesis tells me enough about gravity to know a functional way to make predictions.
I know that if I throw a ball it's going to land on the ground. I know that if I, you know, park my car on a steep hill and it's icy it's going to slide because gravity is pulling it down. Do I understand how the inner the subatomic forces hold these particles together? No. But it doesn't matter because I can still make accurate predictions.
As long as I can make accurate predictions the theory is good enough for me and it's true enough for me. All right. Thanks.