Paramagnetic and Diamagnetic Substances
A paramagnetic substance is one that is weakly attracted by a
magnetic field, usually as the result of unpaired electrons.
A diamagnetic substance is not attracted by a magnetic field
generally because it has only p
Within each group (vertical column), the atomic radius increases with
the period number.
This trend is explained by the fact that each successive shell is larger
than the previous shell.
Within each period (horizontal row), the atomic radius tends
There are a few exceptions to the building-up order prediction for the
Chromium (Z=24) and copper (Z=29) have been found by experiment
to have the following ground-state electron configurations:
1s2 2s2 2p6 3s2 3p6 3d5 4s1
Generally, ionization energy increases with atomic number.
Ionization energy is proportional to the effective nuclear charge
divided by the average distance between the electron and the
Because the distance between the electron
A polar covalent bond (or polar bond) is a covalent bond in which
the bonding electrons spend more time near one atom than near the
Electronegativity, X, is a measure of the ability of an atom in a
molecule to draw bonding el
Electron Configurations of Ions
State the three categories of monatomic ions of maingroup elements.
Write the electron configuration and Lewis symbol for a
Note the polyatomic ions given earlier in Table 2.5.
Note the formation of +2 and +
A formula using dots to represent valence electrons is called a Lewis
An electron pair is represented by two dots.
A electron pair that is between two atoms is a bonding pair. It can
also be represented by one line f
Electron Configurations of Diatomic Molecules
Define homonuclear diatomic molecules and heteronuclear
Describe molecular orbital configurations (homonuclear
Describe molecular orbital configurations (heteronuclear
Dipole Moment and Molecular Geometry
Define dipole moment.
Explain the relationship between the dipole moment and
Note that the polarity of a molecule can affect certain
properties, such as boiling point.
Valence Bond Theory
An electron configuration of an atom is a particular distribution of
electrons among available subshells.
An orbital diagram of an atom shows how the orbitals of a subshell
are occupied by electrons. Orbitals are represented with a
Delocalized Bonding: Resonance
Define localized bonding.
Define resonance description.
Write resonance forms.
Exceptions to the Octet Rule
Write Lewis formulas (exceptions to the octet rule).
Note exceptions to the octet rule in Group IIA and Group
Building Up Principle
Any other allowed configuration represents an excited state.
The building-up principle (or aufbau principle) is a scheme used to
reproduce the ground-state electron configurations by successively
filling subshells with electrons in a