Symbol | Ti |
Atomic number | 22 |
Group | 4 (Titanium group) |
Period | 4 |
Block | d |
Classification | Transition Metal |
Appearance | Silvery grey-white metallic |
Color | Silver |
Number of protons | 22 p+ |
Number of neutrons | 26 n0 |
Number of electrons | 22 e- |
Phase at STP | Solid |
Density | 4.506 g/cm3 |
Atomic weight | 47.8671 u |
Melting point | 1941 K 1667.85 °C 3034.13 °F |
Boiling point | 3560 K 3286.85 °C 5948.33 °F |
Heat of vaporization | 425.2 kJ/mol |
Electronegativity (Pauling Scale) | 1.54 |
Electron affinity | 7.289 kJ/mol |
Oxidation states | −2, −1, 0, +1, +2, +3, +4 (an amphoteric oxide) |
Ionization energies |
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Discovery | William Gregor (1791) |
First isolation | Jöns Jakob Berzelius (1825) |
Named by | Martin Heinrich Klaproth (1795) |
Discovery of titanium Titanium was discovered in 1791 by the clergyman and geologist William Gregor as an inclusion of a mineral in Cornwall, Great Britain. Gregor recognized the presence of a new element in ilmenite when he found black sand by a stream and noticed the sand was attracted by a magnet. Analyzing the sand, he determined the presence of two metal oxides: iron oxide (explaining the attraction to the magnet) and 45.25% of a white metallic oxide he could not identify. Realizing that the unidentified oxide contained a metal that did not match any known element, in 1791 Gregor reported his findings in both German and French science journals:Crell's Annalen and Observations et Mémoires sur la Physique. Around the same time, Franz-Joseph Müller von Reichenstein produced a similar substance, but could not identify it. The oxide was independently rediscovered in 1795 by Prussian chemist Martin Heinrich Klaproth in rutile from Boinik (the German name of Bajmócska), a village in Hungary (now Bojničky in Slovakia). Klaproth found that it contained a new element and named it for the Titans of Greek mythology. After hearing about Gregor's earlier discovery, he obtained a sample of manaccanite and confirmed that it contained titanium. |