Download the App!

Get 24/7 study help with the Numerade app for iOS and Android! Enter your email for an invite.

Like

Report

No Related Subtopics

Carleton College

Rice University

University of Kentucky

01:39

Eugene Schneider

What is a state function? List some examples of state functions.

03:00

Kevin Chimex

What is heat capacity? Explain the difference between heat capacity and specific heat capacity.

01:51

Keenan Mintz

What is meant by the percent ionic character of a bond? Do any bonds have 100% ionic character?

03:16

If two objects, A and B, of different temperature come into direct contact, what is the relationship between the heat lost by one object and the heat gained by the other? What is the relationship between the temperature changes of the two objects? (Assume that the two objects do not lose any heat to anything else.)

Create your own quiz or take a quiz that has been automatically generated based on what you have been learning. Expose yourself to new questions and test your abilities with different levels of difficulty.

Create your own quiz

so like has a couple of interesting properties. And so one property that we're focusing on for this video is the fact that light is a wave, and a wave is something that all slates in a periodic fashion through space and can transfer energy through space through a medium. So, for example, let's say you have some kind of couple and you want to throw it onto some kind of pond. Um, when you throw the pebble into the pond, you'll notice that first, the pebble actually goes into the pond. But then, when that happens, you see that the poll causes a ripple through the pond. And so this can be thought of as a wave because your medium is water and the kinetic energy of the pebble is causing it to go through the water. And there's also a change of potential energy and so that energy transfers through the water in the form of a week. And as for another example, let's say that you're holding on to a piece of rope and you bring the rope up and down, and when you do this, you'll notice that you cause a ripple, like in the pond except through this room. And so you're transferring energy that you're in putting to move the rope on DSO that can manifest itself into the shape of this wave. Um and so light does something very similar. And before going into more detail, I also wanted to know a couple of important characteristics of ways. And so let's say you have some generic wave like so and you have an access morning through it. So at this point, this is like position zero. And so there is, um, positive and negative distance across the weight. And so one important aspect of the wave is the amplitude which is basically the distance from this access to the top most part of your wife or the maximum. And so this amplitude is in units of length, so this could be measured in meters, nanometers, kilometers and so on. And so that's one aspect of eight weeks and waves. Also happy wavelength, which is basically one repeat unit of the wave or one complete oscillation. And so, for example, if you are starting point is here and your end point is here. That is considered one wavelength, which we often note with the symbol Lambda. And, uh, you can define the wavelength in numerous ways. And so it's not just a specific point where you start and end. It's more so the fact that you complete one oscillation. So, for example, you could also say that this is one wavelength, because this is one complete oscillation. Uh, even though you're starting point area and point is a little different and another important aspect of waves are frequencies on DSO frequency is in units one point second and just make this clear. This is a wavelength, um, and so frequency can be thought of as time. But instead of time, it's actually inverse time. And frequency is important because if you want to define the speed of a wave, you need a wave length and frequency. So let's recall that for velocity for a speed oven object, this has units of a length part time, and most commonly it is a means for a second. And so if you want to find the speed of a wave, you need to multiply the wavelength with the frequency to get the right units and so on. You have a wavelength, which is is the units of length. And if you multiply it by frequency, you got Steve. And this makes sense because wavelength can be something like meters and proven C could be something like one over second. And so you get the correct units for a speech and going back to the fact that light is a wave. Light has a specific speed, which is 2.998 times 10 to the eighth meters per second. And so this is commonly denoted as the symbol lower Casey, and you'll be using this information to solve a lot of the problems in the next few videos. And so it's important to note that light travels through space as electromagnetic waves on specifically at 2.998 times 10 to the eighth meter is pair a second. And there are ah lot of different types of electromagnetic radiation that has a characteristic wavelength or frequency that gives us a general sense of the amount of energy that each type carries. And so it's also important to note that energy is proportional to the universe of wavelength or, in other words, thanda Um, and so we can imagine that if we have a smaller wavelength. That means that we have more energy. So, for example, let's say that Lambda is to in this case and Lambda is tough. And so here you can see that if your wavelength is small, your energy value is bigger. And if your wavelength is larger, um, then that means your energy is smaller. Um And so that's another important thing to note for us to really understand why some, um, colors or some of the visible light that you see is more energetic than others or when you're comparing different types of radiation with each other. So in your textbook, there should be some kind of chart that shows theological Oh, magnetic, um spectrum. And so this tells you all the different types of freeze and radiation with specific wavelengths and frequencies on dso all go over a few ones just to talk about briefly. And so one type of radiation is gamma rays, and you may be familiar with this because our son amidst gamma rays, which can be actually harmful to the human body, um and so this often has a We're playing about tens million 12 two tons, the negative a lot of meters so galleries are characteristic in the sense that the wavelength is roughly 10 to 9 of 12 or 10 to the name 11th meters. And so this means that these wavelengths actually carry a lot of energy, because again, the smaller the wavelength, the more energy that it cares. And as another example, X rays have a characteristic wavelength off about 10,000,010 thio, 10 to the ninth meters. And this is also pretty high and energy, but definitely not as high as gamma rays. And so you might recognize X rays whenever you have an X ray bones, Um, and so that is again. One type of electromagnetic radiation and something that you're probably familiar with is actually visible light, Um, which can range from 400 to 700 nanometers. And so this is another type of automatic radiation, specifically because the wavelength is a bit higher and the game raise and the X rays. Um, this actually does not curious much energy, So it's actually not as harmful to the human body. And another important thing to note is that this is the only range that is visible to our eyes. And so the reason why we see color is because we can actually see this range, whereas we can't really see color for X rays and gamma rays since the wavelength falls out of this range. And so one other important things note is that under visible light, we have all the different colors, so you can think of what you give, which is all the colors that human can see. And it's important to note that Violet has more energy than read. Um, for the same argument has shown. Here s so we know that red has a longer wavelength than Violet, and so it has last energy. And lastly, we also have microwaves which are lower and energy than visible light and can range from 10. Want to 10 sending a third meters, and so we have a whole spectrum of different types of radiation, with different frequencies and wavelengths. On DSO. It's important to note that depending on the way length, you have different energy associated with it. So before going into a couple of practice problems, I want Thio briefly mentioned the symbols again that will often see for these kind of problems. And so again, Lambda represents wavelength, which is in units of length and velocity is a symbol for speed, and this is usually in some length part time and see so little Casey is the speed of light, which is two point 2.998 times tens of the 8 m per second. And it's something that I mentioned is frequency, which is the inverse of time. Um, but I forgot to mention that this is represented by new, which is the frequency. And so this is represented by, um, a curly D, which is different from the for a speech. And so it's boring to remember these types of symbols whenever we're running formulas. Um, does all these have the problem? And so now let's go into the first problem, which is to determine the speed of a wave, given that your wavelength is 3.5 times 10 standing in the fifth meters and your frequency is 3.2 times 10 to the second seconds universe. And for this type of problem, you want to use the formula wavelength times frequency is equal to velocity, and so we're given the wailing and the frequency, and so we can find the velocity. So we have 3.5 times 10 to the negative. Fifth, Peter is times the frequency which is 3.2 times 10 to the second in for a second. And so when we plug this into our calculator, we get an answer of 0.112 which we can route into significant figures because that is what we're given for both of these values. And so we end up with 1.1 times 10 to the negative, too. Meter is per a second. Sorry, Meter is for a second, which is our final answer, and Sona. We can also determine the frequency of the wave, given our other knows. And so if we want to find the frequency given that our velocity is 50.1 m for a second and our wavelength is 3.62 m, we can still use the same formula from before. So Lambda Times new is equal to V. And since we're looking for a new, we can isolate it in the equation and so we can divide both sides y lambda. And so we get new is equal to velocity. Orlando and now we can plug our nose into this formula. So in the new is equal to the overland A which is also equal Thio Sorry, which is equal to velocity over Linda. And so we have 50.1. Peter is for a second over three 0.62 m, which is equal to 13.8 seconds in verse. Well, which is your final answer? Um, And whenever we're using frequency, we can also use the units hurts, which is in for a second. And so that is another. How did you use when you're talking about frequency? And now let's go on to your next problem. So let's say that you need to show that the energy of green light is greater than that of the red light, given that your wavelength for green light is 523 nanometers and the wavelength for red light is about 688 nanometers. And so for this problem, we need to understand that energy is proportional to the universe of way line of wavelength, and so we can compare roughly the energy or the quantities that we get using this information. And so we know that for the energy of the green light this is one over 523 nanometers, and for red light is one over 688 nanometers. And so we don't really need to calculate any mouth for this problem because we know that, um, for green light, we have a fraction where the denominator is a smaller number. And for the red light, we have a fraction where the denominator is beer. And so something divided by a bigger number yielding smaller value. So right off the bat, we know that the energy of the green light should be higher than the red. But if we were to put this in our calculator anyway, we end up with 0.191 for Green and we get 0.145 red. And we can still see that the value of energy is greater than that Red. And so we've shown that, um, that this is true. And now for our last problem, let's say that we need to figure out the wavelength, given that the frequency is 5.66 times 10 to the 14th hurts and that the speed of light is 2.998 times turned to the eat meter is for a second and we need to identify what type of wave visit. And so we know that Lambda Times New is evil TV the velocity. And we know that in this case the speed is the speed of light and so to solve for Lambda, we need to divide both sides by new. So we get Lambda is equal to see over new and now we can play in earnings. So Lambda is equal to see which is 2.998 times turned to the I mean er is for a second and we know that our new is 5.66 times 10 to the 14 hurts. And when you put this in your calculator, you get 5.297 times 10 to the negative 7 m, which is 530 nanometers. And so this is actually visible light and specifically a green light, which is your final answer

Periodic Table properties

Chemical Bonding

Molecular Geometry

Gases

08:57

15:13

03:18

08:33

03:47

07:32

13:14

15:00

14:46

06:10

05:07

12:25

06:08

04:37

04:58