Why is osmium the densest element

Why is osmium the densest known element? Ask Question. Asked 6 years, 11 months ago. Active 4 years, 9 months ago. Viewed 6k times. Improve this question. They're very close. Add a comment. Active Oldest Votes. The small atomic radius can be attributed to the following factors : f orbitals are very diffuse and therefore result in poor screening of the electrons further out. As a result, more osmium atoms can pack into a given volume compared to other elements Osmium's relatively high atomic number along with its small atomic radius, as explained above, gives rise to osmium's high density.

Improve this answer. Community Bot 1. So I don't see how the crystal structure, per se , plays into the answer. I fall back to unit cell size, which reflects osmium's small radius, and atomic weight. If I'm missing something, please elaborate. Therefore, all s and, to a lesser degree, p orbitals are contracted. Osmium's 6s orbital its outermost orbital is consequently contracted, so overall osmium's size atomic radius is reduced.

Look here and notice how osmium's radius sticks out like a sore thumb. Pornographic, defamatory, libellous, scandalous, fraudulent, immoral, infringing or otherwise unlawful use of the Images is, of course, prohibited. If you wish to use the Images in a manner not permitted by these terms and conditions please contact the Publishing Services Department by email.

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Nor shall the RSC be in any event liable for any damage to your computer equipment or software which may occur on account of your access to or use of the Site, or your downloading of materials, data, text, software, or images from the Site, whether caused by a virus, bug or otherwise. Jump to main content. Periodic Table. Glossary Allotropes Some elements exist in several different structural forms, called allotropes. Discovery date Discovered by Smithson Tennant Origin of the name The name is derived from the Greek word 'osme', meaning smell.

Glossary Group A vertical column in the periodic table. Fact box. Glossary Image explanation Murray Robertson is the artist behind the images which make up Visual Elements.

Appearance The description of the element in its natural form. Biological role The role of the element in humans, animals and plants.

Natural abundance Where the element is most commonly found in nature, and how it is sourced commercially. Uses and properties. Image explanation. The image suggests the use of the element in making high-quality pen nibs. A shiny, silver metal that resists corrosion. It is the densest of all the elements and is twice as dense as lead. Osmium has only a few uses. It is used to produce very hard alloys for fountain pen tips, instrument pivots, needles and electrical contacts.

It is also used in the chemical industry as a catalyst. Biological role. Osmium has no known biological role. The metal is not toxic, but its oxide is volatile and very toxic, causing lung, skin and eye damage.

Natural abundance. Osmium occurs uncombined in nature and also in the mineral osmiridium an alloy with iridium. Most osmium is obtained commercially from the wastes of nickel refining. Help text not available for this section currently. Elements and Periodic Table History. In , Smithson Tennant added platinum to dilute aqua regia, which is a mixture of nitric and hydrochloric acids, and observed that not all the metal went into solution.

Earlier experimenters had assumed that the residue was graphite, but he suspected it was something else, and he began to investigate it. By a combination of acid and alkali treatments he eventually separated it into two new metal elements, which he named iridium and osmium, naming the latter on account of the strong odour it gave off. Its name is derived from osme the Greek word for smell. Although it was recognised as a new metal, little use was made of it because it was rare and difficult to work with, although it was extremely hard wearing and for several years it was used for pen nibs and gramophone needles.

Atomic data. Glossary Common oxidation states The oxidation state of an atom is a measure of the degree of oxidation of an atom. Oxidation states and isotopes. Glossary Data for this section been provided by the British Geological Survey. Relative supply risk An integrated supply risk index from 1 very low risk to 10 very high risk. Recycling rate The percentage of a commodity which is recycled. Substitutability The availability of suitable substitutes for a given commodity.

Reserve distribution The percentage of the world reserves located in the country with the largest reserves. Political stability of top producer A percentile rank for the political stability of the top producing country, derived from World Bank governance indicators. Political stability of top reserve holder A percentile rank for the political stability of the country with the largest reserves, derived from World Bank governance indicators.

Supply risk. Relative supply risk 7. Young's modulus A measure of the stiffness of a substance. Shear modulus A measure of how difficult it is to deform a material. Bulk modulus A measure of how difficult it is to compress a substance. Vapour pressure A measure of the propensity of a substance to evaporate. Pressure and temperature data — advanced. Listen to Osmium Podcast Transcript :.

You're listening to Chemistry in its element brought to you by Chemistry World , the magazine of the Royal Society of Chemistry. Hello this week the illuminating story of the chemical that christened a light bulb company and helps us to find fingerprints but in the wrong hands can stink to high heaven. To tell the story of the densest element we know here's science broadcaster Quentin Cooper.

Given the whole periodic table to choose from, how to pick a particular element to talk about rather than any other? They've all got their charms and quirks - well, except maybe bismuth. I've never had much time for bismuth - but the deal was I had to single out one.

And then it came to me. A real light-bulb moment. Under-appreciated under-exploited osmium - if any element needs a change of PR this is the one. It's brittle, prone to ponginess and arguably the dunce of the periodic table.

Even the man who discovered osmium treated it rather sniffily. Perhaps in part that's because Smithson Tennant, an English chemist, was also the first to establish that diamond is a form of carbon.

What also didn't help was that his discovery of osmium around came as part of a job lot - he isolated another element, alongside it: also a metal it was hard and yellowy-white and some of its compounds had a kind of rainbow sheen when they caught the light so he gave it a nice shiny name - iridium as in iridescent.

No such luck for the bluish-silver substance he found at the same time : it reeked - or at least some of its compounds did. Tennant described the "pungent and penetrating smell" as one of the new element's "most distinguishing characters". So he called it osmium - osme being the Greek for odour. Not very nice. So osmium is not just an element, it's a smellement, and it's also way beyond lead and gold and platinum as probably the most immensely dense of the whole bunch.

I say probably because it depends how you measure it - and while some rate it as densest others argue it's just pipped by the very thing it was discovered with, iridium. Under pressure. Even osmium is full of fluff, however, in the form of electron clouds that separate the dense atomic nuclei.

Although rarefied, these clouds are robust, and even the immense pressures deep within the planet can only compress solid matter to a modest degree. Far greater pressure is found within the collapsed core of a giant star, a remnant we know as a neutron star. There, matter is in some exotic and ultra-dense form — most probably neutrons, and possibly a few protons and electrons, packed cheek-by-jowl. The latest evidence is against it, though.