The most dense element?

Question

The most dense element?

Answer 1

density is not a property of an element but, i suppose you could say

the largest element is the most dense

-it doesn't have a name yet but they call it Ununoctium

it's number 118

Answer 2

Osmium

Answer 3

osmium...spes gravity=22.61

(mercury=13.6, gold=19.25, iridium=21.78)

Answer 4

Osmium is densest followed by Irridium

Os

Osmium is the densest element known and the hardest of all platinum

group metals (PGMs). It is 10 times harder than platinum itself.

Osmium also has a higher melting point than the other PGMs.

P r o p e r t i e s

Electrical conductivity 0.109 106 cm-1 Ohm-1

Density 22.61 g/cc

Hardness (Brinell value) 3920 MN m-2

Melting point 3050 ºC

Rarity 1x10-4 ppm in lithosphere

Atomic number 76

Atomic weight 190.23

Electrical resistivity 8.12 microhm.cm at 0°C

Thermal conductivity 87 watts/metre/°C

Heaviest element I think is Francium

Francium is a chemical element in the periodic table that has the symbol Fr and atomic number 87. This is a highly radioactive alkali metal that is found in uranium and thorium ores.

This element, which was named for France, was discovered in 1939 by Marguerite Perey of the Curie Institute in Paris. Francium is the heaviest alkali metal and occurs as a result of actinium's alpha decay and can be artificially made by bombarding thorium with protons.

Even though it naturally occurs in uranium minerals, it has been estimated that there might be less than 30 grams of francium in the crust of the earth at any one time. It is the most unstable element among the first 101 and has the highest equivalent weight of any element.

There are 41 known isotopes of francium. With a 22 minute half life, the longest lived isotope of this element is 223Fr which is a daughter isotope of 227At and is the only isotope of francium that occurs naturally. All known isotopes of francium are highly unstable, therefore knowledge of the properties of this element only comes from radiochemical procedures.

A small number of pictures of francium have been taken but only of at the most 200,000 atoms at a time. The pictures were taken by trapping the atoms and using a special fluorescent imaging camera.

4 years ago  

Answer 5

While Osmium seems to be the current favorite, it's not that simple...



From an English site dated 2007:

"The densest element can either be iridium or osmium. It depends how you measure. The two metals are so close in density that they have swapped places in the table several times over the years.

The third densest is easier to pick – it is platinum followed by rhenium, neptunium, plutonium and gold.

Osmium and iridium were discovered in 1803 by English chemist Smithson Tennant. Osmium is very rare and also very hard. It is a silver blue metal.

Osmium is from the Greek 'osme' to smell. Osmium gives off osmium tetroxide which has a strong irritating odour that can damage lungs and eyes. It will also give you a whacking headache. Singularly, osmium tetroxide is used in finger printing because its vapour reacts with minute traces of oil from the skin to form black deposits."

http://www.blurtit.com/q507776.html

See also:

http://www.theodoregray.com/PeriodicTabl...

"Which is the most dense element, osmium or iridium? That honor has changed hands a couple of times over the years. How, you might ask? Because measuring the density of a pure element isn't nearly as straightforward as you might think. For one thing, it can be different for different crystalline forms (allotropes) of the same element. For example, diamond is much denser than graphite: Which is the true density of carbon? Both. In the case of metals, it may be impossible to grow single crystals, so you're measuring the density of a polycrystalline mixture, and the density may depend on details of how the material cooled. Minute impurities can also have a big impact on the density.

So, as measurements and purities were refined over the years, the current best values of osmium and iridium kept changing, and that's how they traded places as most dense of all. I solved this dilemma by only having room to engrave three decimals places of the density, and to three decimal places their density is identical, so I didn't have to pick sides."