Chapter 7 Flashcards
chemical bond
The force that holds two or more atoms together and makes them function as a unit; ionic, metallic, or covalent.
bond energy
The energy required to break a given chemical bond.
ionic bond
A type of attraction between oppositely charged ions; formed when one or more electrons are transferred from a metal to a nonmetal.
ionic
A compound that results when a metal reacts with a nonmetal to form cations and anions.
polar
A type of covalent bond in which the electrons are shared, but not shared equally because one atom attracts the shared electron more strongly than the other atom; this results in a partial + and - charge of different atoms in the substance.
electronegativity
The force with which an atom in a substance attracts electrons from other atoms or ions to itself; the element fluorine has the highest on the periodic table.
delta +
The symbol showing the area of partial positive charge on a molecule’s dipole moment; δ+
delta -
A symbol showing the area of partial negative charge on a molecules dipole moment; δ-
covalent
A chemical bond that involves sharing 1, 2, or 3 pair(s) of electrons between atoms in a molecule; occurs between non-metals.
*ionic compound
Ionic compounds usually form when a metal reacts with a nonmetal, where the metallic atoms lose an electron or electrons, becoming cations (positively charged ions), and the nonmetallic atoms gain an electron or electrons, becoming anions (negatively charged ions).
This is off of google
polarity
Molecules having uneven distribution of charges; determined by subtracting the electronegativities of two different atoms.
polar covalent
A covalent bond in which the electron density is unevenly shared between the two bonded atoms, due to a difference in electronegativity or due to inductive effects.
Non polar covalent
A non-polar covalent bond is a type of chemical bond that is formed when electrons are shared equally between two atoms.
nonpolar
A covalent bond in which the electrons are shared equally by the two atoms; the difference in electronegativity is between 0 and 0.5.
*ionic bond
Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion.
electrostatic
The attractive or repulsive force between two electrically charged objects.
Lewis structure
A representation of a molecule or polyatomic ion showing how valence electrons are arranged among the atoms in the molecule or ion.
duet
A rule that states that since hydrogen and helium have electrons in their 1s orbitals only, they require only 2 electrons to be stable when bonding to other atoms. Of course, since helium’s E.C. is 1s2 it already has 2 and is stable.
octet
The rule that states that atoms of nonmetals form the most stable molecules when they are surrounded by eight electrons to fill their valence orbitals.
bonding pair
A pair of electrons that are shared between the 2 atoms forming a covalent or polar covalent bond; each single, double, or triple covalent bond counts as 1 region of electron density.
lone pair
Electron pairs in a Lewis structure that are not involved in bonding.
single covalent bond
A nonpolar or polar covalent bond in which one pair of electrons is shared by two atoms; represents a single area of electron density.
double
A nonpolar or polar covalent bond in which two pairs of electrons are shared by two atoms; ; represents a single area of electron density.
triple
A nonpolar or polar covalent bond in which three pairs of electrons are shared by two atoms; represents a single area of electron density.
resonance
A condition occurring when more than one Lewis structure can be written for a particular molecule; NOT an isomer because it does not change the substance.
linear
The maximum possible separation for 2 electron pairs that occurs when the electron pairs are forced to opposite sides of a central atom, 180° apart;
Only occurs when a central atom has 2 bonding pairs and 0 lone pairs or when a trigonal bipyramidal substance has 3 lone pairs and 2 bonding pairs.
molecular geometry
The 3-dimensional arrangement of atoms in a molecule.
trigonal planar
The minimum repulsion or maximum separation between 3 electron pairs occurs when the pairs are at the vertices of an equilateral triangle inscribed in a sphere; Only occurs when a central atom has 3 bonding pairs and 0 lone pairs; resulting in a bond angle of 120°
tetrahedral
The minimum repulsion or maximum separation between 4 bonding electron pairs occurs when the pairs are placed at the 4 corners of a geometric figure that has 4 equal, triangular faces; Only occurs when a central atom has 4 bonding pairs and 0 lone pairs; results in a bond angle of 109.5°.
VSEPR
A model used to predict molecular geometry; based on the idea that pairs of electrons surrounding an atom repel each other and that the atoms in the molecule are positioned to minimize this repulsion.
trigonal pyramid
The minimum repulsion or maximum separation between 3 bonding and 1 lone pair of electrons; occurs when the bonding pairs are placed at 3 corners of the triangle; resulting in a bond angle of around or < 109.5°.
electrostatic force
The force between electrically charged objects (like charges repel and opposite charges attract each other).
electron geometry
The arrangement of orbitals containing the bonded and lone electron pairs surrounding the central atom of a molecule or polyatomic ion.
antioxidant
A molecule that reacts easily with free radicals. Some sources include brightly colored fruits and vegetables, vitamin E, and chocolate.
free radical
A molecule or atom that is highly reactive due to having one or more unpaired valence electrons.
isomer
Different molecules that have the same chemical formula with their atoms are bonded differently creating two unique substances.
unpaired electrons
A single valence electron each of which is involved in the formation of a covalent bond or is transferred from a metal to a nonmetal in an ionic bond.
region of electron density
An area represented by shared (bonded) or unshared (lone pairs) of electrons around a central atom.
trigonal bipyramidal
An electron or molecular geometry that includes 5 areas of electron density around a central atom; has different bond angles (90°, 120°, and 180°).
see-saw
A molecule with trigonal bipyramidal electron geometry with 4 bonding pairs + 1 lone pair in the equatorial position with 90° and 120° bond pair repulsions.
T-shaped
A molecule with trigonal bipyramidal electron geometry with 3 bonding pairs + 2 lone pairs of electrons and 90° bond pair repulsions.
octahedral
An electron or molecular geometry that includes 6 total areas of electron density around a central atom with 90° bond angles.
Molecular Surface View
Make sure to know how the red areas represent δ+, blue areas δ- and white is neutral. In polar molecules, the δ+ is used to indicate atoms that electrons are being pulled away from creating areas of partial + charge. The δ- are atoms that are pulling electrons away from the other atoms creating areas of - charge.
