Archive | March, 2016

Absorption Spectrum D.3.31

30 Mar

The next kind of spectrum is called an absorption spectrum, or an absorption line spectrum, and this is basically a rainbow with holes.

When there is a rainbow of colours and you’ve got very specific dark lines popping through on the spectrum. Then with this kind of spectrum you take a hot object and you put a cloud of cooler gas between it.

So for example, this could be the atmosphere of the sun. The middle of the sun is a lot hotter. The middle of the sun is about 15 million degrees. So that would be the hot, hot bulb and then the surface of the sun, the photosphere, the thing you see when we look at it with our eyes, that’s cooler gas.

And so when the light from the sun passes through that cooler gas, the atoms that are in that gas absorb very specific frequencies. Very specific energies as those electrons bounce from one level up to a next, so they are taking energy in very specific colours, very specific wave lengths.

The light emerges from the cloud and you take that light, and you sit at a telescope, and you disperse that light, and you make your rainbow. You see the rainbow with very dark lines in it, as the energy from those lines is then taken out by the cloud from which the light passed through. And this is an absorption line spectrum.

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Continuous spectrum D.3.29

29 Mar

There are three basic types of spectra. This will be about the continuous spectra, which looks like a rainbow of light.

There is a hot object, such as a light bulb or the center of a star. If you look at that hot light bulb – that hot center of the star. You take that light; you pass it through a prism and make rainbows. You will see a continuous spectrum, there are no holes, there are no peaks, and you get the classic rainbow of colors from indigo to red. You can also plot a bright purple or green. And so you can plot the intensity as a function of wavelength, as a function of color. So that’s a continuous spectrum.

The Four Properties of Matter D.3.28

28 Mar

There are solid, liquid, gas, and plasma. What is the common thread between those? How do I go from one phase to another? What is the dominant driver?

It would seem that there’s a different way, a lot of different ways, that you can actually reach these different phases of matter, but one of the really main driving factors is temperature. Going from coldest to hottest, you have solid, liquid, gas, and plasma.

And that’s really the main factor that determines how we go from these different transitions of phases of matter and how we can begin to look at what type of properties we can expect these to exhibit.

So it’s like a temperature sequence – A temperature sequence that’s really the main thing that can determine where your transitions will take place between these different types of matter.

Plasma and Lightning D.3.28

27 Mar

We can witness examples of plasma here on Earth.  One example is electricity.

For instance, when you have a very quick bolt of lightning coming down from the atmosphere.

For a very brief second you may see properties that exhibit that of plasma up near the surface of the clouds that do create these lightning’s.

Plasma D.3.27

26 Mar

What’s plasma? Plasma is one of the phases that’s beyond a gas, so when you take a gas and you heat it to extreme temperatures and densities, it takes on this state known as plasma. That exhibits very particular properties that differentiate it from gas.

What happens to an atom in a plasma? It basically takes on these different properties that normal gas would, for instance, of hydrogen, or helium, or something of that sort.

So plasma becomes like this soup of electrons – it almost takes on this different form of matter that’s not so much liquid as we know as general water or something of the sort, but it’s like an electron soup. We typically see it inside the interior of stars.

Atoms and Molecules D.3.26

25 Mar

We have atoms and then when we take atoms and we put at least two of them together, we make molecules. And then we can start to put various molecules together.

And does matter have different phases and if so what are those phases? And what are the differences of those phases? So matter actually does have four unique phases that we can think of. So we have solid matter, we have liquid matter like your coffee. Your coffee has liquid matter. If you heat it up, it goes to gas and it can evaporate

Carbon Puzzle D.3.25

25 Mar

We’re made out of carbon 12, and carbon has six protons. Then there is carbon-14 dating and there’s carbon-13. What determines those? It’s all carbon, so what’s the difference between, what are those called? You may have a atom of carbon, but you can also have carbon that has more neutrons than the typically carbon-12.

So for instance, you may have a carbon atom that has one extra neutron. That makes it carbon-13, so it’s basically heavier carbon.

And so you can have these different what are called isotopes, which are basically atoms but they may have these additional properties, additional neutrons that make it more massive and make them exhibit different, basically, properties, than their less massive counterparts.

So for example, carbon-14 is often used in radioactive dating components. Are all isotopes radioactive? All isotopes are not radioactive.

 

What is maybe particularly attractive of carbon-14, is that it may have a specific decay rate that may allow us to really nail down that time frame when we’re trying to look at the particular scientific phenomena. So it’s like a clock, a chronometer?