Periodicity Flashcards
What are the structures that elements can have?
Covalent network, covalent molecule, metallic lattice and monatomic.
London Dispersion Forces.
Electrostatic attraction between a temporary dipole and a temporary-induced dipole.
Why does the boiling point increase as the size of the atom increases?
The LDFs increase with the increasing number of electrons- the more electrons the bigger the dipole.
Where are LDFs found?
In all molecules.
Bigger atoms so greater number of occupied energy levels means…
Greater LDFs
More atoms means…
Greater LDFs
What are the many forms of carbon?
Covalent networks are diamond and graphite.
Covalent molecule is fullerene C60
What is covalent radius?
Half the distance between the nuclei of the two of its covalently bonded atoms.
Nuclear charge…
Greater nuclear charge means stronger attraction for outer electrons and so smaller atom.
Increase in screening electrons….
Increase in shielding electrons means bigger atom because it reduces the attraction for the outer electrons causing a screening effect.
What is the ionic radius?
The radius of an ions atom.
Metal ions will be…
Smaller due to the decrease in electron energy levels.
Non-metal ions will be…
Bigger due to the increase of outer electrons causing an increase in energy levels.
What is ionisation energy?
The amount of energy required to remove one mole of electrons from one mole of atoms in the gaseous state.
Ionisation energies are…
Endothermic because they take in energy.
