Chemistry - Ch 8 Flashcards
Chemical bond
whenever two atoms or ions are strongly attached to each other, there is a chemical bond between them
Ionic bond
electrostatic forces that exist between ions of opposite charge
Covalent bond
results from the sharing of electrons between 2 atoms
Metallic bonds
found in metals, such as copper, iron, and aluminum
Lewis symbol
consists of the chemical symbol for the element plus a dot for each valence electron
Octet rule
atoms tend to gain, lose, or share electrons until they are surrounded by eight valence electrons
Lattice energy
energy required to completely separate a mole of a solid ionic compound into its gaseous ions
Born-Haber cycle
thermochemical cycle named after German scientists Max Born & Fritz Haber, who introduced it to analyze the factors contributing to the stability of ionic compounds
Lewis structure
Lewis electron-dot structures; electron pair shared between atoms as a line and the unshared electron pairs as dots
Single bond
sharing of a pair of electrons constitutes a single covalent bond
Double bond
two electron pairs are shared (two lines are drawn)
Triple bond
sharing of three pair of electrons
Bond length
distance between the nuclei of the atoms involved in a bond
Bond polarity
describes the sharing of electrons between atoms
Nonpolar covalent bond
bond in which the electrons are shared equally between 2 atoms
Polar covalent bond
bond in which one of the atoms exerts a greater attraction for the bonding electrons than the other
Electronegativity
ability of an atom in a molecule to attract electrons to itself
Polar molecule
centers of positive and negative charge do not coincide in a molecule
Dipole
whenever a distance separates two electrical charges of equal magnitude but opposite sign
Dipole moment
the quantitative measure of the magnitude of a dipole
Formal charge
the charge the atom would have if all the atoms in the molecule had the same electronegativity (if the bonding electron pair in the molecule were shared equally between its two atoms)
Resonant structures
Lewis structures where the placement of the atoms in two alternative but completely equivalent Lewis structures, but the placement of the electrons is different
Bond enthalpy
enthalpy change for the breaking of a particular bond in one mole of a gaseous substance