Awesome GIFs of Scientific Experiments
1. Hydrogen Peroxide Mixed With Potassium Iodide
2. Explosive Polymerization of p Nitro Aniline
3. Dissolving a tablet in weightlessness
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Fungi Get Into the Holiday Spirit
(Source: National Geographic)
Minimal Posters - Six Women Who Changed Science. And The World.
Ingredients of life
Illustrations of Chemical compounds by Avkari Alon
Bacteria Make Hydrogen Fuel From Water
Most of the renewable energy sources that are under consideration involve an obvious source of energy — light, heat, or motion. But this is the second time this year there has been a paper that has focused on a less obvious source: the potential difference between fresh river water and the salty oceans it flows into. But this paper doesn’t simply use the difference to produce some electricity; instead, it adds bacteria to the process and takes out a portable fuel: hydrogen.
Elements for Clean Energy
Because of its high reactivity and low mass, lithium is used as the charge carrier in the lightest and most energy-dense rechargeable batteries on the market. Ignore talk of “peak lithium.” The element is abundant and environmentally benign.
Used in battery electrodes, superalloys for jet turbines, and magnets, cobalt is relatively abundant. The problem is, 49 percent of the world’s annual supply is mined in the Congo, which is consistently plagued by conflict.
Layers of the rare semimetal tellurium allow cadmium-tellurium solar panels to absorb more light with far less material than conventional silicon panels. Unfortunately, tellurium is produced only in tiny quantities, as a by-product of copper refining.
Neodymium and many of the 16 other rare-earth elements have unusual electron configurations that produce strange but useful magnetic and optical properties. Rare earths have long been ignored and are produced in extremely small quantities.
Perhaps no metal is more resistant to corrosion at high temperatures than rhenium, which, like cobalt, is used in superalloys for highly efficient jet engines. But hardly any metal is rarer than rhenium, which is five times as scarce as gold.
Platinum is highly resistant to corrosion and an excellent catalyst, essential for air-pollution scrubbers such as catalytic converters. Most of the world’s supply comes from just two countries, Russia and South Africa.
20 Things You Didn’t Know About The Periodic Table
How it started, how it’s like solitaire, how to fold it, and how it ends.
Image above: Periodic Table by Lawrence Berkeley National Lab
1 You may remember the Periodic Table of the Elements as a dreary chart on your classroom wall. If so, you never guessed its real purpose: It’s a giant cheat sheet.
2 The table has served chemistry students since 1869, when it was created by Dmitry Mendeleyev, a cranky professor at the University of St. Petersburg.
3 With a publisher’s deadline looming, Mendeleyev didn’t have time to describe all 63 then-known elements. So he turned to a data set of atomic weights meticulously gathered by others.
4 To determine those weights, scientists had passed currents through various solutions to break them up into their constituent atoms. Responding to a battery’s polarity, the atoms of one element would go thisaway, the atoms of another thataway. The atoms were collected in separate containers and then weighed.
5 From this process, chemists determined relative weights—which were all Mendeleyev needed to establish a useful ranking.
6 Fond of card games, he wrote the weight for each element on a separate index card and sorted them as in solitaire. Elements with similar properties formed a “suit” that he placed in columns ordered by ascending atomic weight.
7 Now he had a new Periodic Law (“Elements arranged according to the value of their atomic weights present a clear periodicity of properties”) that described one pattern for all 63 elements.
8 Where Mendeleyev’s table had blank spaces, he correctly predicted the weights and chemical behaviors of some missing elements—gallium, scandium, and germanium.
9 But when argon was discovered in 1894, it didn’t fit into any of Mendeleyev’s columns, so he denied its existence—as he did for helium, neon, krypton, xenon, and radon.
10 In 1902 he acknowledged he had not anticipated the existence of these overlooked, incredibly unreactive elements—the noble gases—which now constitute the entire eighth group of the table.
11 Now we sort elements by their number of protons, or “atomic number,” which determines an atom’s configuration of oppositely charged electrons and hence its chemical properties.
12 Noble gases (far right on the periodic table) have closed shells of electrons, which is why they are nearly inert.
13 Atomic love: Take a modern periodic table, cut out the complicated middle columns, and fold it once along the middle of the Group 4 elements. The groups that kiss have complementary electron structures and will combine with each other.
14 Sodium touches chlorine—table salt! You can predict other common compounds like potassium chloride, used in very large doses as part of a lethal injection.
15 The Group 4 elements (shown as IVA above) in the middle bond readily with each other and with themselves. Silicon + silicon + silicon ad infinitum links up into crystalline lattices, used to make semiconductors for computers.
16 Carbon atoms—also Group 4—bond in long chains, and voilà: sugars. The chemical flexibility of carbon is what makes it the key molecule of life.
17 Mendeleyev wrongly assumed that all elements are unchanging. But radioactive atoms have unstable nuclei, meaning they can move around the chart. For example, uranium (element 92) gradually decays into a whole series of lighter elements, ending with lead (element 82).
18 Beyond the edge: Atoms with atomic numbers higher than 92 do not exist naturally, but they can be created by bombarding elements with other elements or pieces of them.
19 The two newest members of the periodic table, still-unnamed elements 114 and 116, were officially recognized last June. Number 116 decays and disappears in milliseconds. (Three elements, 110 to 112, were also officially named earlier this month.)
20 Physicist Richard Feynman once predicted that number 137 defines the table’s outer limit; adding any more protons would produce an energy that could be quantified only by an imaginary number, rendering element 138 and higher impossible. Maybe.