Chemistry at Home: Milk and Soap
Hey. I'm Melissa.
Jam:I'm Jam.
Melissa:And I'm a chemist.
Jam:And I'm not.
Melissa:And welcome to chemistry for your life.
Jam:The podcast helps you understand the chemistry of your everyday life at home.
Melissa:At home. Okay, Jam. I gave you some instructions.
Jam:Yes. You did.
Melissa:Do you wanna tell me what you did for your experiment this week?
Jam:I'd love to. So I took some milk. Not sure if it matters, but It was 2% milk. I put it in a kind of wide mouthed, short, Pyrex glass dish, Took some food coloring, a couple different colors, dropped it all around on the milk In the milk, I guess, is the right way to say that.
Melissa:And
Jam:and then per your instructions, I put a very small drop of dish soap and had it go right into the middle of the dish of milk.
Melissa:Okay. And what happened?
Jam:It's so weird. Yeah. Nothing happened. So anyway. Anyway, bye guys.
Jam:No. It was very cool, actually. What?
Melissa:Even if nothing happened, though, that is an observation, and you can learn science from nothing happening just For the record.
Jam:I can't wait until you throw that curve ball at me. You give me all these, like, very elaborate instructions of things that don't actually go together at all. You're like, so take a washer hose and some vinegar and some w d forty, A can of Doctor Pepper, some Alka Seltzer, 3 ball bearings.
Melissa:Man, you could do some crazy stuff with that.
Jam:Vegetable oil. Hey. You just yeah. We come out all those things, and then nothing happens. And you're like, alright.
Jam:Well, it's chemistry. Sometimes nothing happens. I'll just be so disappointed. I'll be like, oh my gosh. This seems like it's gonna be a really cool experiment, and then nothing happens.
Melissa:That is true. Sometimes nothing happens, and it is disappointing in chemistry, in science research, etcetera. However, I don't think Children, it's the right age to teach that lesson. You gotta learn to like it before you can be disappointed by
Jam:it. Right. Right. Right. Yeah.
Jam:So it was very cool what actually happened in the real experiment that you really had me do, not the thing when I was just making up. It was like an explosion of color. It was The soap hit. It was just like and all the color just kinda, like, started moving. At first, like, away from the soap, and then it was kinda swirling around itself and kind of, like Yeah.
Jam:It just looks like it was just swirling everywhere. I don't know. It's kinda crazy, and it kept going for a while. I mean, it slowed down, but it It was really just like it kept moving Right. And stuff.
Jam:It was very surprising.
Melissa:Well, do you wanna take a guess at what's going on with that?
Jam:I did have a guess. I I think it may may not be related, but I remember when we talked about soap and grease and stuff back way back at the beginning. Mhmm. Of the podcast where I just I can't remember All the details we talked about, necessarily, but we talked about I I just told you observation I've had where when I've noticed, like, a really greasy dish that might have, like, a little bit of water in it in the in the sink. Mhmm.
Jam:You can kinda see that film of grease or whatever on top. And I've I told you that I'd like to, like, Do a drop of soap and watch it just go and, like, like, scatter away.
Melissa:Right.
Jam:In Almost like it seemed like in fear of the soap. You know?
Melissa:And so
Jam:I've always done that.
Melissa:Theraply wrong.
Jam:I've always done that just to make Doing dishes is a little bit more fun. But in this case, I thought maybe that was something to do with it because the similarities are that they're soap, obviously.
Melissa:And Bright ape?
Jam:Milk isn't greased, but it is definitely fatty. I mean, I don't know exactly the right word for that, but we talked about even Its molecular structure helps in the case of, like, eating something spicy because it has a more lipid y Content to it or something. So I wondered if, like, the hydrophobic thing played into any of this,
Melissa:It's kinda farther down. You're right.
Jam:Those are, like, some puzzle pieces I can point to and say these work together, But I don't exactly know how, I guess.
Melissa:Well, I'm gonna say that you can sum that up by saying it's the return of intermolecular forces. So we've talked a lot about how soap works. You kinda mentioned it. You guys can go all the way back to our very first episode and more recently had an episode about how soap kills COVID nineteen. So soap very basics of soap is that it has one side that is polar or charged.
Melissa:You can learn more about what that Means in-depth in those episodes. And it has one side that's a long chain of nonpolar, non charged neutral. So it is almost like half one way and half the other.
Jam:Mhmm.
Melissa:And fat and Greece are nonpolar, so they want to stick to the nonpolar side of soap. Mhmm. And the charged particles, the positives and negatives, The charged part of soap is going to be attracted to the positives and negatives in water, so water is also polar, and the proteins in milk. So when you drop that soap in, you are watching the interaction of the molecules. You're watching the intermolecular forces at play.
Melissa:So the the soap is is trying to find the fat molecules with one side and the protein and the water molecules with the other, and so it's all moving around. And The the food coloring is moving with it, and so you get to see the movement that happens from the addition of A new molecule into the system and all the molecular interactions that are going on.
Jam:Yes. Yes. Yes. Yes. Dang.
Melissa:So you're watching the intermolecular forces. I mean, obviously, not a molecular level, but you're seeing sort of the results of all those molecular interactions.
Jam:So if you if you hadn't put the food coloring in, would it be super hard to even tell anything's happening?
Melissa:Probably so. I mean, maybe you could see that it was moving, but you might even just think it's moving because you put a drop in the middle.
Jam:Right. Right.
Melissa:But I've never tried it without food coloring. So if you're doing this at home with a kid, I suggest that you kind of do exactly what I just did with jam. You can put the food coloring on, ask them, what do you think is gonna happen? I didn't get to ask him that because He was doing it without me. After it happens, you can ask them to tell you what's going on and and basically encourage them to make observations.
Melissa:Oh, it's Still moving. It slowed down, but it's still moving. All the colors spread out. Then you can ask them what they think is going on. And they're probably, Obviously, not gonna get that jargony language unless you're doing it with someone who's already been in some chemistry classes, an older kid, you know, maybe a teenager.
Melissa:But they can talk about, oh, the soap moves the milk around, and any kind of conclusion that they come to About why that's happening is getting them to think critically about what's going on even at a young age. Even if that answer Doesn't exactly line up with the jargon. If they're they're making accurate statements about trying to figure out what's going on, That's a good place to start for kids. And then let them, as always, try new things. So they can say, What's gonna happen if you do this without food coloring?
Melissa:Kids love food coloring, so usually the question is, what happens if we do this with all the food coloring? They do that a lot. So you can try that. You can get them to try it with different liquids. You can say, do you think this is gonna happen in water?
Melissa:I think if you did it in water, it'd probably be pretty boring. Mhmm. You could try it with different kinds of milk that you have at home or heavy cream or anything like that. You can try with different kinds of soap, hand soap, dish dish detergent, anything like that. You can try drizzling the soap or putting, it on a Q tip and putting the Q tip in and moving the Q tip around.
Melissa:You can try all different kinds of things. So I would let them ask questions. What if we do this? Can we do this? And My answer when I'm doing these kinds of experiments with kids is always, yep.
Melissa:Let's do it. Mhmm. Anything you're interested in trying and seeing what happens, That's an investigative mind at work, so we wanna encourage that. So definitely let them do that if they wanna try it over again and put different kinds of food coming around. And while this is happening, you can ask them, do you think is gonna happen?
Melissa:Wow. That's cool. Wow. Do you wanna try something different? Oh, I like that idea.
Melissa:Dia, you know, be very encouraging. Ask a lot of questions. Get them to practice verbalizing why or what they think, and those are Good ways to do science with kids. Also, a fun fact, we did this at my college graduation party. So at my college graduation party, I had set up all these little experiments.
Melissa:I think there was a a slime Set up, and I don't remember all of them, but that was the 1st time I did this experiment with the milk and the food coloring.
Jam:Mhmm.
Melissa:And it was really fun, and the college graduates Loved it. The people in college that I invited to my graduation party loved it. So I think maybe teenagers will think they're Too cool, but this is a fun one for any age. I mean, Jam had fun doing it, and he's a dad. So Yeah.
Melissa:Absolutely.
Jam:It was a lot of fun. I definitely would like to maybe try it a few more times too and try different things if I had a good time. There's like just like you said I mean, you start to think of different Things to do, like, I'd love to try it without the food coloring and see if I can notice any changes if I look very closely. Mhmm. Or just try different combinations of colors and stuff.
Jam:But because I didn't know exactly how it was gonna work, I just picked some random colors and stuff, and and it might be kinda cool to see if there's would be some that would blend together well or or whatever. But, yeah, it was a lot of fun. I think it's I think even teenagers, if they'd let themselves just try it, would have fun doing it.
Melissa:I think so too. Also, you can try different types of food coloring. Maybe gel food coloring would move differently than the ones you drop on and stuff. There's lots of fun things you could do. Great.
Melissa:Well, chemistry is cool. I'm glad you had a fun time.
Jam:Absolutely. Thanks for teaching me, or I guess first just Send them me on a wild experiment and then teach them me later.
Melissa:Yeah. I think this is a fun way to do it. We're like we said, we're open to any kind of feedback that you guys give, but I really have enjoyed Just telling you to do an experiment and then seeing what happens.
Jam:Me too. It's actually kinda fun, especially because, like, I don't have to wait too long to have it be explained, But it's pretty fun just not knowing anything ahead of time. It's like as if you were just kinda giving a chemist, like, some instructions And no information. Like, normally, I wouldn't be neat shouldn't really do a lot of experiments, but these are all safe ones. And I just don't know anything, so it's it's so great to just be totally blind.
Melissa:Yay. Thanks for having a good attitude about it, And thanks to all of you guys for listening. Let us know if you have any ideas or if there's any experiments that you've already done with your kids that you'd like us to go over. We'd be happy to do that.
Jam:This episode of Chemistry For Your Life was created by Melissa Clooney and Jam Robinson. And we'd like to give a special thanks to E Robinson who reviewed this episode.
