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Oh my god! It's my first post in ages!I'm really sorry I haven't posted at all recently, I've been under a lot of pressure with work from school, especially with this anodising project... Anyway, back to oranges and lemons...I read the other day that the only reason that oranges and lemons taste and smell different it to do with different proportions of the two optical isomers of limonene, the molecule responsible for the taste and smell of quite a few different citrus fruits (but mainly oranges and lemons)! That's so cool!Yeah! When you think about it, oranges and lemons are quite different. Most people would happily eat a slice of orange but very few would do the same with lemon, their tastes are very different. But... What are optical isomers?When you have a carbon atom with 4 different functional groups, you have two possible arrangements for the functional groups that are different. They're actually the mirror image of each other, which is why they're called optical isomers. Here's and example: The optical isomers, more commonly called enantiomers, are mirror images of each other but are not the same. In the case of oranges and lemons, it becomes much more difficult to see because of the size of the molecule, but here it is. The carbon that has the 4 different functional groups is called a chiral carbon or chiral centre, because these optical isomers can also be called chiral molecules. A brief bit of historyThe existence of optical isomers was first discovered in 1848 by Louis Pasteur, while he was studying tartaric acid, a byproduct of wine making. His discovery stemmed from a discovery made earlier that century by a french physicist named Jean-Baptiste Biot. He discovered that Tartaric acid was optically active. What does optically active mean?If a solution or substance is optically active, it means that it rotates the plane of light going through it by a certain angle. What Jean-Baptiste Biot discovered when he shone a ray of polarised light (light that oscillates on only 1 plane) through tartaric acid, was that it rotated the plane of light by 12 degrees. No one knew why this phenomenon occured until Pasteur discovered that the acid produced two different types of crystal. The two crystals were mirror images of each other. Pasteur called them chiral crystals from the greek 'kheir' for hand, and deduced that the molecules that make up these crystals must also be chiral. Chiral molecules are still commonly called left and right handed today due to their resemblance to the left and right hand (mirror images of each other). ThalidomideThe existence of chiral molecules was not widely considered important (generalisation) until a drug called thalidomide came around. Although there's a good chance you've heard the story before, it's quite important today in the pharmaceutical industry and drug discovery. Thalidomide was a drug designed to prevent the morning sickness that comes with pregnancy, and it did it very well. To keep it short, the problem was that thalidomide has two enantiomers that were produced in equal quantities when the drug was manufactured. One enantiomer prevented morning sickness very well with few side effects, while the other enantiomer caused birth defects. Almost 10,000 babies were born with deformed limbs, and less than 40% of these children survived. I think this topic is pretty interestingI don't know about you but the fact that just the different arrangements of functional groups around an atom can have such a huge effect on the properties of the molecule as in the cases of limonene and thalidomide, is amazing. Those two aren't 'freak' cases either, there are plenty of other examples like glucose and carvone (spearmint and caraway). I hope you enjoyed reading thisChristmas holidays are coming up for me and although I'll be studying for my IB mock exams, I also hope to post a few more articles here. Even though I don't have time to write many posts here, I try to keep posting interesting science on my social medias so if you want to stay up to date, follow on my social medias.
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Chemistry and chocolate! the 2 best things in the world!Sorry physics. And Johnny Marr. And ice cream. Sorry... It can't be that complicated can it?You'd be surprised! Chocolate is an incredibly versatile thing! But all chocolate is literally the same...Sure, they are 'all the same' to you because chocolate is mainly sold in bars and that's what people mainly eat, and those chocolate bars are mainly made from the same type of chocolate. The aim of chocolate bars is to be a solid at room temperature, but to melt in your mouth. Making this type of chocolate involves some cool chemistry. Chemistry? But chocolate is a food...So what? Literally everything is chemistry anyway. Moving on though, everything starts with the cocoa bean in the cocoa pod on the cocoa tree. If you were to try a cocoa bean (not suggested) you would find that it tastes nothing like chocolate at all. This is because there are a number of chemical changes that need to occur within the beans to get the flavours going. This starts with picking all the pods and then literally throwing them on the ground in a pile to rot and ferment for two weeks. Read more to learn about the interesting and unusual properties of chocolate...What is anodising?Aluminium reacts with the air to form a natural layer of aluminium oxide which provides it with decent corrosion resistant surface. Anodising is the process of artificially thickening that layer for dyeing, extra gluing strength or just for increased corrosion resistance. For a chemistry experiment I'm trying to anodise aluminiumFrom what I'd seen on YouTube it looked quite simple. I can tell you now it isn't as easy as it looks. After 4 months of research, I think I've found out everything about how to do it and decided to share the information so it's all in one place :). Read more for my own guide of how to anodise in the lab or at homeWoah woah woah slow down. What even are semiconductors?They're the materials that transistors are made from. Transistor are the little guys that power your phone and laptop, and are the little guys that sent man to the moon. If you read my previous post you'll know the interesting story of how semiconductors came about. Today however I want to talk about doping Doping? You mean like... drug doping??Actually, you can kind of put it that way if you want, I'll explain why but first we need to start off with the basics. Silicon bonds like this and forms a 'square' lattice. Read more to learn about the technology behind every single one of your electronic devices...I used to wonder, what can we even use graphene for? A sheet of carbon only an atom thick, what use is it if it's so small? But actually I'm starting to realise it's possible applications. I watched a video on carbon nanotubes and just when I thought there were no more surprises, I find that rolling carbon nanotubes up in different ways gives you different electrical conductivities! Just by changing the rolling a little bit, you can create a semiconductor, a metal or a half metal! This makes me super excited!!!
Hehe. Back to my point, this is very exciting! This means that from 1 element we can make conductors, semiconductors, and half metals! Wait, what on earth is a half metal?Now this is something that's super cool. A half-metal is any substance that acts as a conductor to electrons of one spin orientation, but as an insulator or semiconductor to those of the opposite orientation. Just one problem, Graphene isn't magnetic :(But maybe we can make it magnetic? Well here's where I get super excited again! If you add hydrogen to the graphene lattice it makes it magnetic! Here, just watch the video! makes me wonder, Maybe in 50 years we won't be complaining about limited oil resources, we'll be worrying over limited carbon resources. Graphene and Carbon Nanotubes are pretty promisingOver and out :)I've been thinking a lot about plastic recentlySounds weird but I'm starting to realise how big of a problem plastic is. It started when I scrolled through my twitter feed and saw the following from New Scientist One third of all plastic in the open ocean comes from microfibres shed from washing our clothes This really amazed me. Whenever I think of plastic in the oceans I think of plastic bags and bottles, but I had never thought about microplastics. They must be incredibly hard to remove. Sure, you could run a really fine filter through sea water but then you'd catch everything else too like the plankton and other natural components of the ocean. So how can you remove such small plastic particles? And then there's bottles.Reusable plastic bottles. Seems like an easy fix. Use a reusable one. But that reusable bottle is still plastic too! When it breaks it still ends up in a landfill or an ocean. So use a metal one. This is where another tweet, again from New Scientist, really blew my mind You'd need to use a steel water bottle 500 times for it to be better than a plastic one I had always thought metal was the answer, but I'd never stopped to really think about it, but now it seems almost obvious. The amount of energy that goes into extracting metals from their ores is huge. Take iron, you need to extract the iron ore out of the ground which takes tremendous amounts of energy, then try and purify the ore, and then put it into a blast furnace to make the pure iron, which uses tons and tons of coal/coke which gives off tremendous amounts of carbon dioxide Plastic bags are used for 12 minutes on average, then stay on the earth for almost 500 years It's not as easy as it seemsHow would you remove plastics? Drag a massive net through the ocean? That would take out all the animals too, and a lot of plastic is no longer just on the surface, quite a bit of it has sunk down to the sea bed too. Food for thoughtOver and out :/I did it :0Curiosity is a bad bad thing sometimes. When I dipped my fingers into the hydroxide it became slimy and I realised that the hydroxide was literally reacting with the fats in my skin and making soap. Huh?An oil (triglyceride) will react with a strong base to form a soap, in a saponification reaction. It's quite an interesting area actually. The triglyceride breaks up into a glycerol and 3 fatty acid molecules, the negative fatty acid molecules then ionically bond with the Na+ from the base. Another interesting thing I learnt (from an amazing book called Napoleon's Buttons), is that different bases make hard and soft soaps which is cool. Potassium soaps are hard and Sodium soaps are soft. I don't know why that's the case but I intend to find out! :0 I know, i know this is super random but i thought it was interestingOver and out :)I'm always on the lookout for scientific content.That's just the way I am, but it took me a while to find the best books, series, documentaries and more. Now, I'm going to share what I've found to be the best of the best in terms of interesting science stuff! Hope you agree! BOOKS!Don't hate on books guys, they're pretty amazing sources of information. NAPOLEON'S buttons
RATING - 10/10 AGE - 15 AND UPSeven brief lessons on physics
RATING - 9/10 AGE - 16 AND UPThe DISAPPEARING spoon
RATING - 10/10 AGE - 13 AND UPStuff matters
RATING - 10/10 AGE - 14 AND UPSeries and documentariesAnother amazing place to find information. Also an excuse so your parents let you watch TV. Genius Season 1 - Albert Einstein
RATING - 9/10 AGE - 14 AND UPEveryday Miracles - BBC
RATING - 9/10 AGE - 13 AND UPInside Einstein's mind - NOVA
RATING - 10/10 AGE - 15 AND UPYoutube ChannelsWho doesn't love YouTube? A great channel for anyone who loves Chemistry (me). NileRed makes lots of cool chemicals from chemicals that are readily available at a pharmacy or supermarket. He also does an Edible Chem series where he makes chemicals used in food and tries them. This channel is my personal favourite. RATING - 10/10 AGE - 15 AND UPMinutePhysics
RATING - 10/10 AGE - 14 AND UPVeritasiumRATING - 10/10 AGE - 14 AND UPThat's it for now!I'll keep updating this with more stuff as I discover it. Let me know if you have any suggestions of good books to read, series and documentaries to watch or youtube channels to subscribe to! over and out :)How do our brains decide what's sweet?We say fructose is sweeter than glucose or sucrose but why? What chemical property makes fructose sweeter? Then there's the question of how our mouths detect that 'sweetness' and how our brains interpret it.
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