1
00:00:00,750 --> 00:00:12,050
The world we live in is made of things. Billions and billions of different things, like pickles

2
00:00:12,050 --> 00:00:17,449
and pianos and dump trucks and octopi. And even though these things seem totally different,

3
00:00:17,449 --> 00:00:21,929
they're all made of the same stuff, just combined in different ways. To give you an idea of

4
00:00:21,929 --> 00:00:26,690
how this combining works, let's take something apart. Let's start with this bowl of macaroni

5
00:00:26,690 --> 00:00:31,589
salad. If you were to reverse a recipe for macaroni salad, you'll see it's made by mixing

6
00:00:31,589 --> 00:00:37,950
together a bunch of ingredients, like macaroni, mayo, vinegar, vegetables, and mustard. This

7
00:00:37,950 --> 00:00:41,990
type of combining is called a mixture. When you make a mixture, you're combining two

8
00:00:41,990 --> 00:00:47,630
or more things together without actually changing the chemical identity of those things. Like

9
00:00:47,630 --> 00:00:53,030
mud, for example. The soil and water in mud haven't actually changed. There's still

10
00:00:53,030 --> 00:00:58,729
soil and water. You've just created a mixture of soil and water. Mud. It turns out that

11
00:00:58,729 --> 00:01:03,070
But macaroni salad is actually a mixture of mixtures, because many of the ingredients,

12
00:01:03,070 --> 00:01:06,150
like mayo and mustard, are already mixtures themselves.

13
00:01:06,150 --> 00:01:10,409
Which is nice for us, because if we look closely, we'll see the three main types of mixtures

14
00:01:10,409 --> 00:01:11,489
that exist.

15
00:01:11,489 --> 00:01:15,810
The size of the particles in a mixture determines the type of mixture.

16
00:01:15,810 --> 00:01:19,569
On one end of the scale is a suspension, like our muddy water example.

17
00:01:19,569 --> 00:01:23,689
You get this if you take big chunks of something and mix it with something else so those chunks

18
00:01:23,689 --> 00:01:25,450
are just floating around.

19
00:01:25,450 --> 00:01:27,129
Take runny mustard, for example.

20
00:01:27,129 --> 00:01:31,750
see a bunch of little particles like mustard seeds, pepper, allspice, and minced shallots

21
00:01:31,750 --> 00:01:36,849
all floating around in a liquid. In this case, vinegar and water. This is called a suspension

22
00:01:36,849 --> 00:01:41,569
because you've got particles of one thing suspended in another. Now, on the other end

23
00:01:41,569 --> 00:01:45,709
of the spectrum is a solution. The particles in this mixture are so small, they are the

24
00:01:45,709 --> 00:01:50,049
actual molecules. A solution is sort of like a suspension of molecules, where one type

25
00:01:50,049 --> 00:01:55,329
of molecule is blended or dissolved with another. Vinegar is an example of a solution where

26
00:01:55,329 --> 00:02:00,430
the molecules of acetic acid are blended with molecules of water. The chemical properties

27
00:02:00,430 --> 00:02:04,489
of the molecules haven't changed, they're just evenly mixed together now. Salt water

28
00:02:04,489 --> 00:02:09,509
and carbonated soda are both examples of solutions where other molecules are dissolved in water.

29
00:02:09,509 --> 00:02:14,030
The last type of mixture is called a colloid, which is somewhere between a suspension and

30
00:02:14,030 --> 00:02:18,090
a solution. It's when you take two materials that don't dissolve and you make the particles

31
00:02:18,090 --> 00:02:23,009
so small that they can't separate. Mayo is what happens when you take oil and water,

32
00:02:23,009 --> 00:02:27,330
don't mix, and you bind them together, usually with the help of another substance called

33
00:02:27,330 --> 00:02:32,449
an emulsifier, in the case of mayo it's lecithin found in eggs, and now you're left with really

34
00:02:32,449 --> 00:02:37,469
small globs of oil hanging out with really small droplets of water. Whipped cream, hair

35
00:02:37,469 --> 00:02:43,270
spray, styrofoam, and jello are all other examples of colloids. So, let's get back to

36
00:02:43,270 --> 00:02:48,270
macaroni salad. You've got colloids like mayo, suspensions like mustard, and solutions like

37
00:02:48,270 --> 00:02:52,629
vinegar, but you've also got celery, shallots, and all other vegetable chunks that are also

38
00:02:52,629 --> 00:02:57,210
part of the salad. These aren't mixtures, really, but we can break them up, just like a TV can be

39
00:02:57,210 --> 00:03:01,370
broken up into smaller and smaller complex component parts. In the case of vegetables,

40
00:03:01,590 --> 00:03:06,389
if you keep breaking things up, you'll eventually end with thousands of complex organic molecules,

41
00:03:06,770 --> 00:03:15,229
things like ATP synthase, and RNA transcriptase, and water. So now, once we've unblended all the

42
00:03:15,229 --> 00:03:20,370
solutions, unmixed all the colloids, separated all the suspensions, and taken apart all of our

43
00:03:20,370 --> 00:03:25,289
vegetables, we've reached the end of what we can unmix physically. What we're left

44
00:03:25,289 --> 00:03:29,490
with is a whole bunch of molecules, and these molecules remain chemically the

45
00:03:29,490 --> 00:03:33,389
same whether they are by themselves or thrown together in a salad. If you want

46
00:03:33,389 --> 00:03:38,370
to separate these guys even further, we need to unmix things chemically, which

47
00:03:38,370 --> 00:03:42,830
means we need to start breaking some bonds.