ATOMIC STRUCTURE PERIODIC TABLE 3 Flashcards
Why does first ionisation
energy decrease between
group 2 to 3?
● Decreases between 2 to 3 because in group 3
the outermost electrons are in p orbitals.
● Whereas in group 2 they are in s orbital, so
the electrons are easier to be removed.
Why does first ionisation
energy decrease between
group 5 to 6?
● The decrease between 5 to 6 is due to the group 5 electrons in p orbital which are single electrons.
● In group 6 the outermost electrons are spin paired, with some repulsion.
● Therefore the electrons are slightly easier to remove.
Does first ionisation increase or decrease between the end of one period and the start of the next? Why?
● Decrease
● There is an increase in atomic radius
● Increase in electron shielding
Does first ionisation increase
or decrease down a group?
Why?
● Decrease
● Shielding increases → weaker attraction
● Atomic radius increases → the distance between the outer electrons and nucleus increases → weaker attraction
● Increase in the number of protons is outweighed by an increase in distance and shielding
Describe the structure, forces
and bonding in every element
across period 2.
● Li & Be → giant metallic; strong attraction between positive ions and delocalised electrons; metallic bonding
● B & C → giant covalent; strong forces between atoms ; covalent
● N2, O2, F2, Ne → simple molecular; weak intermolecular forces between molecules; covalent bonding within
molecules and intermolecular forces between molecules
Describe the structure, forces
and bonding in every element
across period 3.
● Na, Mg, Al → giant metallic ; strong attraction between positive ions and delocalised electrons ; metallic bonding
● Si → giant covalent ; strong forces between atoms ; covalent
● P4, S8, Cl2, Ar → simple molecular; weak intermolecular forces between molecules; covalent bonding within molecules and intermolecular forces between molecules
