The Periodic Table graphic is at last complete - all of the elements, with a plethora of data for each, colour coded to indicate trends in each across the table. View in larger size here: http://wp.me/p4aPLT-dE

Also available to purchase in HUGE on the site’s Redbubble page.

tlema1617 asked:
How are pans nonstick?

Pans are usually made non-stick using Teflon, the trade name for the polymer polytetrafluoroethene (PTFE). The polymer is a long chain of repeating units, one of which is shown below. Although PTFE is the major polymer used, not all non-stick coatings are necessarily teflon; other fluoropolymers can also be used.

image

Elemental fluorine is very reactive, but within PTFE, the fluorine atoms have an electron structure that is very stable - as such, they don’t react with other atoms easily. As the carbons in PTFE are surrounded by the fluorine atoms, they are also shielded from reacting. This prevents food from sticking to the pan.

The obvious question to ask is how the slippery non-stick coating can be made to stick to the pan in the first place. The surface of the metal pan must be roughened to make it easier to stick the polymer to it; the teflon is then applied in coats, and baked on to the pan in order to ensure it remains attached. It doesn’t attach to the metal as such, but this process makes it very difficult for it to seep out of the roughened surface of the metal.

You can read more detail here. Hope that answers the question!

Resurrecting an old but relevant graphic for Easter - the chemistry of chocolate: why any aphrodisiac effect is probably no more than a placebo, and why it’s toxic to dogs: http://wp.me/p4aPLT-5j

Today’s post takes a topical look at the different structures of chocolate - and why it might be good idea to stash any Easter chocolate in the fridge if you don’t plan on consuming it right away… http://wp.me/p4aPLT-dt

An attempt to answer one of life’s big questions with today’s graphic - why does bacon smell so good? http://wp.me/p4aPLT-dm

(Also, setting aside some time to respond to asks in the next few days, as I’ve been a bit busy this week. If you’ve sent one through, don’t worry - they’ll all get a response.)

Also also… kudos to freshphotons for the idea for this aroma chemistry series!

As the Periodic Table graphic’s taking a little time, here’s a peak at how part of it’s currently looking. Very much still a work in progress - the sharper-eyed amongst you will probably noticed there’ve already been a few tweaks from the initial key I posted a short while ago. 

The categories for each element are: melting point (blue, ˚C); boiling point (red, ˚C); Pauling electronegativity (purple); density (green, g/cm3 for solids, g/L for gases); first ionisation energy (pink, kJ/mol); and radius (orange, empirical, Å).

Hoping to have it finished within the next few days!

could you set fire to the moon?

Interesting question!

For a fire, we’d need oxygen, fuel and heat. First off, let’s consider the atmosphere of the moon. We usually think of the moon as being surrounded by vacuum, but it does actually have a very thin atmosphere - it’s less than one trillionth of the density of Earth’s atmosphere (at sea level). The gases in this atmosphere come from the radioactive decay of elements in the crust of the moon, and also from the solar wind. The reason we don’t consider it to have an atmosphere, is because it has to be constantly replenished by these sources - the gases are continually being lost to space.

The composition of the atmosphere isn’t well known, but it’s estimated to be around 80,000 atoms per cubic centimetre. Of these, around 40,000 are argon, 2,000-40,000 are helium, 70 are sodium & 17 are potassium; small amounts of oxygen have been detected, but this is a very small proportion. Since fire needs an atmosphere of around 16% oxygen to burn, the moon’s atmosphere wouldn’t contain enough.

As far as fuel goes, we’d also be struggling. The moon’s crust is made of a variety of oxygen-containing compounds. The major compounds are silica (SiO2, ~45%), alumina (Al2O3, ~15-24%), calcium oxide (CaO, ~12-16%), iron oxide (FeO, ~6-14%), and magnesium oxide (MgO, ~7.5-9%). This mixture of compounds is non-combustible, so wouldn’t be able to act as a fuel for our fire, even if we could somehow provide enough oxygen and heat.

So, in short, you couldn’t (easily) set fire to the moon!

All of the ‘Colourful Chemistry’ graphics so far are now available on the site as one download: http://goo.gl/4qUpfm

handsoffire asked:
What's the deal with monosodium glutamate? I've heard that the glutamic acid in it isn't toxic as it has been believed, but I also hear that it is used to make lab rats gain weight. What's going on chemically and is it safe?

Glutamates add an ‘umami’ flavour to foods, which is a Japanese word essentially meaning ‘pleasant savoury taste’. It’s naturally found in a wide range of foodstuffs - a few examples are meats, parmesan & tomatoes, amongst many others. 

When you add salt to a dish, you obviously perceive the taste as salty. When you add MSG, you’re also stimulating the taste receptors on your tongue, but in this case those that respond to the ‘umami’ flavour.

MSG was in the past linked to migraines, hypertension & heart disease - to be fair, it still is if you do a quick google search. This kicked off when a Doctor wrote in a scientific journal (not specifically about MSG) that he experienced uncomfortable symptoms after visiting Chinese restaurants. From this rather ambiguous anecdote came ‘Chinese Restaurant Syndrome’, which was (incorrectly) linked specifically with MSG.

Some research on rodents showed that MSG could have unpleasant effects - but this research was carried out using ridiculous amounts of MSG per kg of body weight, far more than a human would comparably consume. One test used 20g per 100g of rat food - a huge amount when you consider that the average consumption figure for UK adults is around 4g a week.

A review of the research in 2006 found that there was no consistent clinical data to support the claims that MSG caused a variety of conditions. All countries that have any form of food licensing department have passed MSG as safe at normal dietary levels. So, MSG really gets a horrendously bad rep for no good scientifically proven reason. Neither glutamic acid, or MSG (the sodium salt of glutamic acid) are in any way toxic at levels regularly consumed.

Hope that makes it a bit clearer!

Back to basics today, with ‘A Brief Guide to Types of Organic Chemistry Formula’: http://wp.me/p4aPLT-cv