transition metal trends

iron use

construction and manufacturing

titanium and tungsten

technologically important metals

platinum and technetium

medically important metals in drugs and imaging

catalysts

platinum, palladium, rhodium and iron

how are transition metals used in dyes and pigments

compounds can be highly colourful

natural abundance of transition metals

ranges from extremely common to extremely rare

even z (atomic number)

generally more common than those with odd z

transition metals found as ores

oxides, sulphides, carbonates and silicates

iron

• Hematite

• Magnetite

Cobalt

cobaltite

copper

• native metal

• Chalcopyrite

• Chalcosite

Mercury

Cinnabar

Pt, Pd, Rh, Ru, Ir

alloys of native metals

Ag, Au

native metal

Ni

• Pentlandite

• Millerite

W

• wolframite

• scheelite

atomic radius trends

3d electrons shield 4s electrons from the nuclear charge, so only a gradual change from Cr to Zn. 4d are larger than 3d in general. The 4d and 5d metals have similar radii. This is because of the shielding of 4f electrons in the 5d elements.

melting point

the peak in melting points comes from the increasing strength of metallic bonding as Cr/Mo/W are density

elemental density

The peak in density comes from a combination of the increasing metallic bonding and increasing atomic weight

ionisation energy

The elements tend to be harder to ionise across periods. The (n + 1)s electrons are removed first. The nd electrons shield the (n + 1)s electrons, so only a gradual in IE1. The increase in IE1 is from the increasing nuclear charge exerting more attraction on the valence electrons (although this is shielded by the d electrons)

electronegativity

the elements tend to be more electronegative across the periods

electronic structure of 3d metal ions

Removal of an electron from a d-block element stabilises the nd-orbitals, making them lower in energy than the (n+1)s orbital

oxidation states of the 3d metals

All of the transition metals can be oxidised and some show a wide number of oxidation states. Metals with lower oxidation states are more ionic in their bond character while those with higher oxidation states tend to be more covalent.