introduction to transition elements Flashcards
Why are Sc and Zn categorized as d block elements?
They have their highest energy electrons in a d sub shell/orbital.
Give 3 typical properties of d block elements.
High mp/bp, shiny, good conductors of heat & electricity, malleable, ductile.
What are common uses of iron?
Construction, tool production.
What are common uses of copper?
Electrical cables, water pipes.
What are common uses of titanium?
Aerospace industry, medical applications such as joint replacements.
Why do copper and chromium not follow the normal pattern of filling 4s before 3d?
A half filled d5 sub shell and full d10 sub shell give additional stability to the atoms.
Which electrons are lost first when d block elements form ions?
4s.
Define ‘transition metal’.
A d block element which forms at least 1 ion with a partially filled d sub shell.
Why are Sc and Zn not transition metals?
Sc only forms 3+ ion which has an empty d subshell; Zn only forms 2+ ion which has a full d subshell. Transition elements must have a partially filled d sub shell.
State the 3 properties of transition metals that other metals do not have.
Variable oxidation states, coloured compounds, compounds and elements can act as catalysts.
What colour is potassium dichromate?
Bright orange.
What colour is cobalt II chloride?
Purple pink.
What colour is nickel II sulphate?
Green.
What does the colour of transition element compounds vary with?
Oxidation number.
What is the catalyst in the Haber process?
Fe.
What is the catalyst in the contact process?
V2O5.
What is the catalyst in catalytic decomposition of hydrogen peroxide?
MnO2.
What is a homogenous catalyst?
Catalyst and reactants are in same physical state.
What is a heterogenous catalyst?
Catalyst is in different physical state to reactants.
Why do Zn compounds dissolve to form a colourless solution?
Colour is associated with presence of a partially filled d orbital; Zn only forms Zn2+ ions; Zn2+ ions have a full d sub shell.
