Chemical Bonding Flashcards
chemical bond
mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together
purpose of chemical bonds
decrease potential energy of atoms
increase stability of atoms
types of chemical bonds
ionic bond
covalent bond
difference between types of chemical bonds
the way the electrons are redistributed
ionic bond
the transfer of electrons to other atoms
results from the electrical attraction between large numbers of cations and anions
bond between atoms with an electronegativity difference of 1.7 or greater
formed between metals and nonmetals
covalent bond
the sharing of electrons between two bonded atoms
bond between atoms with an electronegativity difference of 1.7 or less
formed between nonmetals
determining factor of type of chemical bond
difference in the bonded atoms’ electronegativities
type of bond between atoms of the same element
covalent bond
types of covalent bonds
nonpolar covalent bond
polar covalent bond
nonpolar covalent bond
covalent bond in which the bonding electrons are shared equally by the bonded atoms
results in a balanced distribution of electrical charge
bond between atoms with an electronegativity difference between 0.0 and 0.3
polar covalent bond
covalent bond in which the bonded atoms have an unequal attraction for the shared electrons
results in an imbalanced distribution of electrical charge
bond between atoms with an electronegativity difference between 0.3 and 1.7
molecule
a neutral group of atoms that are held together by covalent bonds
simplest unit of a molecular compound
molecular compound
covalent compound
chemical compound formed by two or more bonded atoms through the sharing of electrons
chemical formula
indication of the relative numbers of atoms of each kind in a chemical compound by using atomic symbols and numerical subscripts
molecular formula
chemical formula of a molecular compound
diatomic molecule
a molecule containing only two atoms
interaction between charged particles in chemical bonds
approaching nuclei and electrons attract each other
2 nuclei repel each other
2 electron clouds repel each other
bond length
bond distance
distance between 2 bonded atoms at their minimum potential energy
bond energy
energy (in kJ⁄mol) required to break a chemical bond and form neutral isolated atoms
octet
4 pairs of electrons
8 electrons
octet rule
states that chemical compounds tend to form so that each atom has an octet of electrons in its highest energy level by gaining, losing, or sharing electrons
exceptions to the octet rule
hydrogen and helium are stable with 2 electrons (1 pair of electrons)
aluminum and boron are stable with 6 electrons (3 pairs of electrons)
some elements can be surrounded with more than 8 electrons when combined with highly electronegative elements
electron-dot notation
electron-configuration notation in which only the valence electrons of an atom of a particular element are indicated by dots placed around the element’s symbol
explanation of a Lewis structure
atomic symbols represent nuclei and inner-shell electrons
dot-pairs or dashes between two atomic symbols represent electron pairs in covalent bonds
dots adjacent to only one atomic symbol represent unshared electrons
unshared pair
lone pair
pair of electrons that is not involved in bonding and that belongs exclusively to 1 atom
structural formula
indicates the kind, number, arrangement, and bonds of atoms in a molecule
does not indicate the unshared pairs of atoms in a molecule
single bond
single covalent bond
covalent bond produced by sharing 1 pair of electrons between 2 atoms
represented by 2 dots in between 2 atoms’ atomic symbols or by 1 dash
multiple bonds
multiple covalent bonds
covalent bonds produced by sharing more than 1 pair of electrons between 2 atoms
types of multiple bonds
double bond
triple bond
double bond
double covalent bond
covalent bond produced by the sharing of 2 pairs of electrons between 2 atoms
represented by 2 side-by-side pairs of dots or by 2 parallel dashes
triple bond
triple covalent bond
covalent bond produced by the sharing of 3 pairs of electrons between 2 atoms
represented by 3 side-by-side pairs of dots or by 3 parallel dashes
determining factor of need for multiple bonds
satisfaction of the octet rule for each atom
resonance
bonding in molecules or ions that cannot be correctly represented by a single Lewis structure
covalently bonded networks
compounds which can be pictured as continuous 3-dimensional networks of bonded atoms
does not contain individual molecules
ionic compound
compound composed of positive and negative ions that are combined so that the numbers of positive and negative charges are equal
formula unit
simplest collection of atoms from which an ionic compound’s formula can be established
crystal lattice
orderly arrangement of ions in an ionic compound which minimizes their potential energy
maximizes attraction and minimizes repulsions of ions
lattice energy
energy released when 1 mole of an ionic compound is formed
used to determine strength of ionic bonds
electrostatic forces
force that holds ions together in ionic compounds
very strong overall attraction between positive and negative charges