 Now I have this other terminology that we had on there, which is a dilution series. And this dilution series, where they have the same components, but at different concentrations. So, at a stock, in lab we used a dye, right? And we had pre-tubes, right? And here we took one male into that one, 0.2 males into this one, and 0.1 male into that one. To this one we added 9 males, so we had 1 to 1 plus 9, or 1 to 10. This one we brought up to 10 males again, so we had to add 9.8 males. So, in this case, so that gives us 0.2 to 0.2 plus 9.8, which is going to give us a 1 to 50 dilution. So that 0.2 males is 1.50 of the 10 males. So, we can see then, in this one where we've got 1 tenth, we'd have to add 9.9 males yet. So in this case we've got 0.1, or 0.1 plus male plus 9.9 males. So that's going to be 1 to 100. So there's 1 tenth to 100 tenths, so that's a 1 to 100 dilution. So they're all in this case coming from the stock, and so there are series that were making these components. So in this case it's just terminology, but it's related to our third group. And this is a form you'll see used often in the lab, serial dilutions. This is a series of dilution, the same dilution factor. Now, up in this dilution series, which we just did, we had a factor of 10 and a factor of 5th in 100. They were all dilutions of the same stock, but they had different dilution factors. So in our serial dilution, we're going to set these up so that they all have the same dilution factor. So you can find this on your lab sheet. So hopefully you've read it and you may already understand it. So we have these set of tubes here. We're going to say that each one of these tubes has one male in it. And we're going to move one male from this tube into this tube, which is going to bring it up to two males initially, but then we're going to mix it up well. Get it a homogeneous mixture and then move one male from that tube to the next. We'll do the same thing. We'll mix it well and move a male to the next tube, repeat the male after we mix it, and then finally here we'll move a male from there. So this is a serial dilution. Each one is diluted from the previous dilution into the next one. So we're seeing this one male plus one male is a one to two. Next dilution is also a one to two because it's one plus one to two, but it is a dilution of a one to two. So now it's really a one to four. We can put this one concentration of one to two. So the concentration of this tube is one fourth what it was in the original tube because it's one half of this one half. So then we're going to do another one to two, but now that's going to be one eighth, right? So we see the same thing going on. We're repeating the same dilution factor. In this case the dilution factor is two. So each one you can see is getting our denominator is doubling. So we go one half, one fourth, one eighth and one sixteenth and then one thirty seconds. So by doing these sets of serial dilution we've gone from our undiluted sample here in the first tube to a one to thirty two dilution. So the concentration of what we're diluting our stock here in tube one is one thirty second, right? Or we could say that it's a thirty two fold, right? Total dilution is supposed to be thirty two, right? And the other thing we can say that this is a two fold serial dilution. So the terminology tells us that it's a serial dilution because we're doing a series of two fold dilutions. So in this case our definition says that it has the same dilution factor. In this case the dilution factor is two, right? So let's just do another quick example here to just show another one. So here I've got another set of tubes. In this case we have our stock here in this first tube, right? And then we have our serial dilution one. We have nine mills in each one and we're moving one mill across mixing it. So there nine plus one, right? One, so that's a one to ten. Now if we mix it we're going to take one mill of that. We only have nine mills of that left since we're taking one mill away. But the concentration is based on that one plus the nine. So we're taking one into this nine. So it's one right here again plus the nine with one. So we've got another one tenth, but this is what? One tenth over one tenth. So that's going to be one to a hundred. Likewise we take one mill over. So we've got another one ten. But since it's one to ten over one to ten it'll be another ten fold, which from a hundred would now be one to a thousand. And here again another one to ten would give us one to ten thousand ten. And here a one to ten would be one to a hundred thousand. Now we have other ways to write this. Okay so we've got one to ten. We could just write this one to ten square. We could write this one. Hold on. The ten cubed one over ten to the fourth or one over ten to the fifth. So this is kind of a better way of writing it and having those two zeros and those are equivalent. Another way that we can write this without the fractional form is we can say that's ten to the negative one, ten to the negative two, ten to the negative three, ten to the minus four, ten to the minus five. So if you remember your thing about negative exponents, right, those are equivalent. One tenth is ten to the one. So if you see in this case ten to the minus two, it's the same thing as one over ten to the plus two. So these are all ways of writing that in this case. This is a serial tenfold dilution. So in this case from our undiluted concentration, which we're saying one, by doing one, two, three, four, five dilutions, we've gotten a hundred thousand fold dilution of this stop. So it's another tool. It's a frequently used tool in doing that. So if you get this thing up here, you want to know what your final concentration is, right, or after your dilution, your final concentration is equal to your starting concentration times your dilution. For instance, if you had a concentration we have there on the paper, blue-cut grams per mil, and we added one mil plus nine mils of water, right, to give us a one over one plus nine is a one to ten dilution. Then we would say four grams per mil, and one tenth is equal to zero point four grams per mil. And that seems reasonable, point four gram is a tenth, right, a four gram. So by diluting it tenfold, we've got one tenth the concentration. Let me, I don't know what that line is there, let me get that worked out. That's one over one plus nine, one over ten, let me get that there. Okay, so that's kind of a lot of information there. I say it's in your book, it's in the lab and you've hopefully done a lab on this, so you get a notion of what's going on with dilutions. But this is kind of a, kind of went, wanted to go over the information on that sheet with you to kind of verbally explain what's going on with that. And that will conclude this kind of introduction and dilutions. And I'll set up another video to talk about solutions. Thanks for listening.