Atomic Structure

Question 1

Definition of first ionisation energy

Answer 1

The enthalpy change when ONE MOLE of electrons is removed from ONE MOLE of GASEOUS atoms to form ONE MOLE of GASEOUS positive ions

Question 2

Factors affecting ionisation energy

Answer 2

DISTANCE FROM NUCLEUS (changes as atomic/ionic radius changes) - further, weaker nuclear attraction

NUCLEAR CHARGE - more protons, greater nuclear attraction

SHIELDING - full shell of electrons weakens nuclear attraction for further out shells

CHARGE ON ION - more positive ion, more energy to remove electrons

Question 3

How does sub-shell shielding affect successive ionisation energies?

Answer 3

There is an electron in a new sub-shell which means it is slightly shielded by the previous sub-shell and is more easily removed

Question 4

What is the effect of spin-pair repulsion on successive ionisation energies?

Answer 4

This is the first electron resulting in a doubly occupied orbital which means it feels a repulsion and is easier to remove

Question 5

Define relative isotopic mass (Ir)

Answer 5

The mass of an atom of an isotope relative to the 1/12th of the mass of an atom of carbon-12

Question 6

Define relative atomic mass (Ar)

Answer 6

The mean mass of an atom of an element relative to 1/12th the mass of an atom of carbon-12

Question 7

Define relative molecular mass (Mr)

Answer 7

The sum of the relative atomic masses in a simple covalent molecules and diatomic elements

Question 8

Define relative formula mass (Fr)

Answer 8

The sum of the relative atomic masses in compounds with giant structures