1. TRANSITION METALS ヾ(＠⌒ー⌒＠)ノ

d block elements

transition metals (only worry ab titanium to copper)

definition of transition metal

a metal that can form one or more stable ions with an incomplete d sub shell

d sub shell contains up to 10 electrons

transition metals must for atleats 1 ion that had between 1-9 electrons in the d subshell

scandium and zin

cannot form ions w between 1-9 electrons

electron configuration rules

• electrons full up the lowest energy subshells first

• electrons fill orbitals singly before they start sharing

4s sub shell has lower energy that 3d subshell

so 4s subshell is filled up first singly then doubled up, with exceptions

chromium

4s subshell has 1 electron and 3d subshell has 5 electrons for stability

copper

4s subshell has 1 electron and 3d subshell has 10 electrons for stability

transition metal electron configuration

transition metal atoms form positive ions

4s electrons are removed first, then 3d electrons

writing the electron configuration of a transition metal ion

• write down the electron configuration of the atom

• work out how many electrons have been removed to give the ion’s charge

• remove that number of electrons from the electron configuration taking them from the 4s orbital first then 3d orbital

scandium and zinc are not transition metals

their stable ions do not have incomplete d sub shells

scandium only forms Sc³⁺ which has an empty d orbital

scandium electron configuration [Ar]3d¹ 4s^2, scandium ion electron configuration [Ar]

Zn only forms 1 stable ion Zn²⁺ which has a full d subshell

zinc electron configuration [Ar]3d¹⁰ 4s², zinc ion electron configuration [Ar]3d¹⁰

physical properties of transition metals

• extremely high density

• high melting and boiling points

chemical properties of transition metals

• can form complex ions

• form coloured ions

• good catalysts

• exist in variable oxidation states

TITANIUM

• Ti²⁺ violet

• Ti³⁺ purple

VANADIUM

V²⁺ violet

V³⁺ green

VO²⁺ (+4) blue

VO₂⁺ (+5) yellow

CHROMIUM

Cr³⁺ green

Cr₂O₇^2- (+6) orange

MANGANESE

Mn²⁺ pale pink/colourless

MnO₄^2- (+6) green

MnO₄^- (+7) purple

IRON

Fe²⁺ pale green

Fe³⁺ yellow/purple

COBOLT

Co²⁺ pink

NICKLE

Ni²⁺ green

COPPER

Cu2+ pale blue

incomplete d subshells cause special chemical properties of transition metals