Download Periodic Trends

Periodic Trends
Atomic Radii
• Defined by the edge of its
orbital but since the edges
are fuzzy, difficult to
determine
• Atomic Radii – half the
distance between the nuclei
of identical atoms that are
bonded together
Atomic/Ionic Radii
Arrange the following groups in order
of increasing atomic size:
• Rb, Na, Be
• Sr, Se, Ne
• Fe, P, O
Ionization Energy
• An electron can be removed from an atom if
enough energy is used
• Ionization energy – the energy required to
remove one electron from a gaseous neutral
atom
A + energy  A+ + e-
Ionization Energy
Ionization Energy
Arrange the following groups in order
of increasing first ionization energy:
• Rb, Na, Be
• Sr, Se, Ne
• Fe, P, O
Electron Affinity
Electron Affinity – the energy change when an
electron is added to a gaseous neutral atom,
exothermic process
A + e-  A- + energy
Electron Affinity
Order the atoms in each of the
following sets from the least
exothermic electron affinity to the
most.
• N, O, F
• Al, Si, P
Electronegativity
• applies when an atom is in a compound NOT
alone
• Electronegativity – measure of how strongly
an atom attracts electrons when it is in a
compound
• Fluorine (the most electronegative element) is
assigned a 4.0 and then all the others were
determined by comparison
Electronegativity
Predict some of the properties of
element 117 (Uus):
• What will be its electron configuration?
• What element will it resemble most
chemically?
• What will be the formula of the neutral binary
compounds it forms with sodium, magnesium,
carbon, and oxygen?