Physics

Iridium

Iridium

Iridium Definition Iridium (symbol Ir) is a rare, whitish-yellow element that is the most corrosion-resistant metal known. Although only certain molten salts and halogens are corrosive to solid iridium, finely divided iridium dust is much more reactive and can be flammable. Its atomic number 77; .....

Read More »

Osmium

Osmium

Osmium Definition Osmium is a hard, brittle, bluish-white metallic element that is the densest naturally occurring element. It is the densest naturally occurring element, with a density of 22.59 g/cm3. Its atomic number 76; atomic weight 190.2; melting point 3,000°C; boiling point 5,000°C; spec.....

Read More »

Ruthenium

Ruthenium

Ruthenium Definition Ruthenium (symbol Ru) is a rare, silvery-gray metallic element that is hard, brittle, and very resistant to corrosion. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most .....

Read More »

Rhodium

Rhodium

Rhodium Definition Rhodium (Rh) is a rare, silvery-white metallic element that is hard, durable, and resistant to acids. It is a noble metal and a member of the platinum group. It has only one naturally occurring isotope, 103Rh. Its atomic number 45; atomic weight 102.905; melting point 1,966°C;.....

Read More »

Palladium

Palladium

Palladium Definition Palladium (Pd) is a malleable, ductile, grayish-white metallic element that occurs naturally with platinum. Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs). These have similar chemical proper.....

Read More »

Technetium

Technetium

Technetium Definition Technetium is a silvery-gray, radioactive metallic element. It was the first element to be artificially made, and it is produced naturally in extremely small amounts during the radioactive decay of uranium. Its atomic number 43; melting point 2,200°C; specific gravity 11.50.....

Read More »

Hafnium

Hafnium

Hafnium Definition Hafnium is a bright, silvery metallic element that occurs in zirconium ores, with symbol Hf. Because hafnium absorbs neutrons better than any other metal and is resistant to corrosion, it is used to control nuclear reactions. Its atomic number 72; atomic weight 178.49; melting .....

Read More »

Scandium

Scandium

Scandium Definition Scandium is a soft, silvery, very lightweight metallic element that is found in various rare minerals and is a byproduct in the processing of certain uranium ores. Its atomic number 21; atomic weight 44.956; melting point 1,540°C; boiling point 2,850°C; specific gravity 2.99.....

Read More »

Promethium

Promethium

Promethium Definition Promethium is a radioactive metallic element of the lanthanide series, which is does not occur in nature but is prepared through the fission of uranium. It is a chemical element with symbol Pm. Its atomic number 61; melting point 1,168°C; boiling point 2,460°C; valence 3. .....

Read More »

Thulium

Thulium

Thulium Definition Thulium is a soft, silver-gray metallic element of the lanthanide series with symbol Tm. Its Atomic number 69; atomic weight 168.934; melting point 1,545°C; boiling point 1,727°C; specific gravity 9.3; valence 2, 3. Like the other lanthanides, the most common oxidation state .....

Read More »

Samarium

Samarium

Samarium Definition Samarium is a silvery-white metallic element of the lanthanide series that exists in several forms and has seven naturally occurring isotopes. Its atomic number 62; atomic weight 150.36; melting point 1,072°C; boiling point 1,791°C; specific gravity approximately 7.50; valen.....

Read More »

Lutetium

Lutetium

Lutetium Definition Lutetium is a silvery-white metallic element of the lanthanide series that is used in nuclear technology. It is the last element in the lanthanide series, and it is traditionally counted among the rare earths. Its atomic number 71; atomic weight 174.97; melting point 1,663°C;.....

Read More »