This weekend I had another go at FameLab, the three minute science communication competition. Again, the competition was brilliantly hosted by @KennyWebster and his team at ThinkTank - the science museum in Birmingham. The standard was exceptionally high, and it was a great afternoon packed with talks on a range of topics from double pendulums to evil basil plants! I wish everyone going forward to the next round the best of luck: and I'd recommend to everyone that they should go and watch the regional final, the judges will have a tough time! (Wed 29th January, again at ThinkTank)
I hadn't had much time to prepare this year and it showed a bit: I wasn't as comfortable presenting as I normally am.
I spoke on the amazing properties of water and I have posted the transcript below if you fancy learning something new.
Afterwards, the judges Jon (@Jonwoodscience) and Josephine (picture, right) gave me some great advice on the topic and the way I presented.
Along with a friend who registered but chickened out at the last minute, I plan to go up and have another go, entering the heats in Manchester next month! Wish me luck!!
Water, water everywhere, but it's not as simple as you think...
Water is made up of two hydrogen atoms and an oxygen atom: H 2 O. If it was as simple as that, you would expect the shape of a water molecule to be linear: all the atoms lined up in a row, but that's not the case. Water has a kinky secret, and it's all about electrons...
Each hydrogen atom has one electron and each oxygen atom has 6 available for bonding. Each hydrogen uses one of its own and one of the oxygen's electrons to form a bond, leaving 4 remaining electrons around the oxygen. These pair off with one another and are called 'lone pairs'. This gives us four groups of electrons around the oxygen atom: two bonds to hydrogen atoms and two lone pairs. These four groups are negatively charged and therefore all want to be as far apart from one another as possible.
Imagining your hands are lone pairs and your legs are bonds to hydrogen atom shoes, take a big step forward and lift your arms into a "Y" shape. You are now a water molecule! As the lone pairs are not visible, the water molecule is not linear, but kinky at an angle of 104.5 degrees to be precise. Which is lucky for me, as I can't do the splits...
So why is this kink so special? Well, the electrons in the bonds holding the hydrogen atoms to the oxygen are not evenly distributed: the oxygen has a larger and stronger positive core and so pulls the electrons closer to it: making the hydrogen end of the bond slightly positive and the oxygen end slightly negative. This is called a polar bond. (nothing to do with bears).
As they say, opposites attract, and my two negative lone pair hands are desperate to grab onto some positively charged hydrogen shoes and form what is called a 'hydrogen bond'. Now this is what makes water different. Because of having two lone pairs and two polar bonds, each molecule can form a hydrogen bond to four others: one in each hand and one to each leg. At room temperature, when the molecules are moving around, they won't get the chance to form all four, but as the temperature lowers, all the water molecules come together to form a circus act: making a large structure with big gaps in. Ice. These gaps mean that ice is less dense than water and floats on the top, unlike most molecules, which huddle like penguins when they get cold and form a solid that is denser than the liquid.
There are other molecules that can hydrogen bond, but not to the same extent: ammonia is the equivalent of having 3 legs and hydrogen fluoride one leg and three arms. Because they have less chance of grabbing onto one another when flying around at room temperature, these molecules are all gases. And because they'll always be a spare arm or leg, they cannot form a structure like ice.
So that is why a little kink makes water so wonderful: I urge you to go forth and hydrogen bond!! (although circus training might be recommended)
I hadn't had much time to prepare this year and it showed a bit: I wasn't as comfortable presenting as I normally am. I spoke on the amazing properties of water and I have posted the transcript below if you fancy learning something new.
Afterwards, the judges Jon (@Jonwoodscience) and Josephine (picture, right) gave me some great advice on the topic and the way I presented.
Along with a friend who registered but chickened out at the last minute, I plan to go up and have another go, entering the heats in Manchester next month! Wish me luck!!
Water, water everywhere, but it's not as simple as you think...
Water is made up of two hydrogen atoms and an oxygen atom: H 2 O. If it was as simple as that, you would expect the shape of a water molecule to be linear: all the atoms lined up in a row, but that's not the case. Water has a kinky secret, and it's all about electrons...
Each hydrogen atom has one electron and each oxygen atom has 6 available for bonding. Each hydrogen uses one of its own and one of the oxygen's electrons to form a bond, leaving 4 remaining electrons around the oxygen. These pair off with one another and are called 'lone pairs'. This gives us four groups of electrons around the oxygen atom: two bonds to hydrogen atoms and two lone pairs. These four groups are negatively charged and therefore all want to be as far apart from one another as possible.
Imagining your hands are lone pairs and your legs are bonds to hydrogen atom shoes, take a big step forward and lift your arms into a "Y" shape. You are now a water molecule! As the lone pairs are not visible, the water molecule is not linear, but kinky at an angle of 104.5 degrees to be precise. Which is lucky for me, as I can't do the splits...
So why is this kink so special? Well, the electrons in the bonds holding the hydrogen atoms to the oxygen are not evenly distributed: the oxygen has a larger and stronger positive core and so pulls the electrons closer to it: making the hydrogen end of the bond slightly positive and the oxygen end slightly negative. This is called a polar bond. (nothing to do with bears).
As they say, opposites attract, and my two negative lone pair hands are desperate to grab onto some positively charged hydrogen shoes and form what is called a 'hydrogen bond'. Now this is what makes water different. Because of having two lone pairs and two polar bonds, each molecule can form a hydrogen bond to four others: one in each hand and one to each leg. At room temperature, when the molecules are moving around, they won't get the chance to form all four, but as the temperature lowers, all the water molecules come together to form a circus act: making a large structure with big gaps in. Ice. These gaps mean that ice is less dense than water and floats on the top, unlike most molecules, which huddle like penguins when they get cold and form a solid that is denser than the liquid.
There are other molecules that can hydrogen bond, but not to the same extent: ammonia is the equivalent of having 3 legs and hydrogen fluoride one leg and three arms. Because they have less chance of grabbing onto one another when flying around at room temperature, these molecules are all gases. And because they'll always be a spare arm or leg, they cannot form a structure like ice.
So that is why a little kink makes water so wonderful: I urge you to go forth and hydrogen bond!! (although circus training might be recommended)
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