In 1831, vanadium was rediscovered by Nils Gabriel Sefstrom, and del Rio’s work was verified by Friedrich Wohler. ![]() However, in 1805 it was claimed that del Rio had mistaken chromium for a new element, causing del Rio to retract his discovery. He then changed the name to erythronium (meaning red in Greek) as many vanadium salts turned red when heated. He named the element panchromium (meaning all-colours in Greek) as it produced salts of many different colours. In 1801, Andres Manuel del Rio discovered vanadium in an ore called brown lead (now called vanadinite). Display: Titanium metal pellet and rod, titanium oxides – TiO (beige), Ti 2O 3 (purple), TiO 2 (white, also known as titania), titania-containing sunscreen and white paint, and rutilated quartz (quartz contained rutile TiO 2) Titanium alloys are also used in the aerospace industry as they are light, strong and durable. The main use of titanium is as titanium dioxide, used as a white pigment in many applications including paint, toothpaste and sunscreen. Klaproth, upon becoming aware of Gregor’s work, confirmed that he had discovered the same element. In 1795, Martin Heinrich Klaproth independently discovered titanium in the mineral rutile and named it after the Titans of Greek mythology. He concluded that it contained iron oxide and a second oxide which he could not identify, and which he attributed to a new element that he named menachite. William Gregor discovered titanium in 1791 when examining the mineral ilmenite. Display: Scandium metal crystals and bicycle seat post clamp (bolt made from scandium alloy) The main use of scandium is in aluminium alloys to increase their strength for specialised applications in the aerospace industry and for sports equipment. Pure samples of scandium metal were not produced until 1937 as it is neither particularly easy to extract, abundant nor useful. ![]() It was detected ten years later in 1879 in the minerals gadolinite and euxenite by Lars Fredrik Nilson who named it after Scandinavia ( Scandia in Latin), as he was Swedish. Looking for something specific in this course? The Resource Index compiles links to most course resources in a single page.Scandium was predicted by Dmitri Mendeleev in 1869 who named it ekaboron. ![]() Lecture 29: Transition Metals: Crystal Field Theory Part II Lecture 28: Transition Metals: Crystal Field Theory Part I Lecture 27: Introduction to Transition Metals Lecture 26: Chemical and Biological Oxidations Lecture 25: Oxidation-Reduction and Electrochemical Cells By the end of the unit, viewers should be able to calculate electrochemical cell potentials, identity which compound is the better oxidizing agent, draw energy diagrams that explain why one cobalt compound is blue and another red, and explain how a chelator works to treat acute lead poisoning. ![]() Viewers can observe some of these special properties for themselves as spectacular color changes afforded by solutions of nickel and cobalt salts are demonstrated. Revisiting the concept of atomic orbitals, we discuss how the occupation of electrons in d-orbitals gives rise to the special properties of d-block metal-containing complexes. Whereas metals in group I and II of the periodic table are only oxidized by one and two electrons, respectively, transition (d-block) metals are capable of achieving multiple oxidation states. In Unit IV, we continue to consider chemical reactions but now focus on reactions that involve the loss (oxidation) and gain (reduction) of electrons. Unit IV: Transition Metals & Oxidation-Reduction Reactions
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