Slides in this set
· Is the repetition of both physical and chemical
properties of the elements both across
periods and down groups.
· This can coincide with repetition in electronic
· (Ask for examples for the element Ar and Mg)…read more
· There are two definitions of atomic radius:
· Covalent Radius half the distance between
the nuclei of atoms of the same element
covalently bonded within the same molecule.
· Van der Waals Radius half the distance
between the nuclei of two atoms of the same
Element from two different molecules…read more
· The atomic radius decreases across period 3:
· The nuclear charge increases, so the electrons are
drawn closer to the nucleus.
· There is no additional shielding for the increase in
nuclear charge. Results in a drop in the ionization
3p orbital's have additional shielding provided by 3S2 electrons this is
evidence of decrease in ionization energy.
Mg- 1s2 2s2 2p6 3s2 1t I.E= 738 KJ mol-1
Al- 1s2 2s2 2p6 3s2 3p1 I.E= 578kj mol-1…read more
conductivity across period 3
· This increases from Na to Al, due to the
number of delocalized electrons they're are
able to carry, current increases so it's ability to
conduct electricity increases.
· The elements Si to Ar have very low electrical
conductivity (close to zero ) because they
bond covalently. So the electrons are not free
to conduct electricity.…read more
Trends Melting and boiling points
across period 3:
· These are linked to the bond strength and
structure of the elements.
· Na to Al are metals the melting and boiling
points increase because the nuclear charge
and the size of the atoms increase. So the it it'
s a greater attraction, and more energy is
needed to melt or to boil them…read more