Chemical Bonding and Molecular Structure

chemical bonds

strong attractive forces that hold molecules together

chemical processes

breaking and forming of chemical bonds

physical processes

interactions between molecules

octet rule

an atom tends to bond with other atoms until it has eight electrons in its outermost shell, thereby forming a stable electron configuration similar to that of the noble gas elements.

ionic bonding

one or more electrons from an atom with a smaller ionization energy are transferred to an atom with a greater electron affinity

electrostatic forces

ionically bonded atoms are held together by .....

covalent bonding

an electron pair is shared between two atoms

polar covalent bonds

when bonding is partially covalent and partially ionic

ionic bonds

when two atoms with large differences in electronegativity react, there is a complete transfer of electrons from the less electronegative to the more electronegative atom

cation

atom that looses electrons

anion

atom that gains electrons

oxyanions

polyatomic anions containing oxygen

neutral compound

when positive and negative charges baance each other out

ionic compounds

have high melting and boiling points due to the strong electrostatic forces between the ions. They can conduct electricity in the liquid and aqueous states only

covalent bond

when two or more atoms with similar eletronegativities interact, they share electrons to achieve....

double bond

when two pairs of electrons are shared in a covalent bond

triple bond

when three pairs of electrons are shared in a covalent bond

covalent bond

can be characterized by two features: bond length and bond energy

bond length

the average distance between the two nuclei of the atoms involved in the bond

increases, closer together, decrease

as the number of shared electron pairs .........., the two atoms are pulled ............, leading to a ....... in bond length.

bond energy

the energy required to separate two bonded atoms

increases, increases

the strength of the bond ....... as the number of shared electron pairs ...........

bonding electrons

the shared valence electrons of a covalent bond

nonbonding electrons

the valence electrons not involved in the covalent bond

lone electron pairs

another name for nonbonding electrons

Lewis Dot Structure

the chemical symbol of an element surrounded by dots, each representing one of the s and/or p valence electrons of the atom

V-0.5Nbonding-Nnonbonding

Formal Charge

resonance structures

when two or more nonidentical Lewis structures can be drawn

a double headed arrow

resonance structures are expressed with

small, larger

a lewis structure with ........... formal charge is preferred over a lewis structure with .......... formal charge

12

Sulfate has ........ valence elctrons

polar covalent bonding

occurs between atoms with small differences in electronegativities.

electronegative

the electron is pulled towards the more ........... element in polar covalent bonding

dipole movement

small separation of charge generates a .......

Nonpolar Covalent bonding

occurs between atoms that have the same electronegativities

nonpolar covalent bonds

occur only in diatomic molecules with the same atom

N2,O2,F2,Cl2,Br,I2,H2

elements that exist under normal conditions only as diatomic molecules

coordinate covalent bond

the shared electron pair comes from the lone pair of one of the atoms in the molecule

Lewis Acid

a compound that can accept an electron pair to form a covalent bond

Lewis Base

a compound that can donate an electron pair to form a covalent bod

VSEPR theory

the actual geometric arrangement of the bonds and different atoms is obtained using ........ obtained using Lewis Structures

Valence Shell Electron Pair Repulsion Theory

VSEPR theory is called in full:

polar molecule

if the dipole moments of the bonds do not cancel each other out (by pointing in opposite directions)

net dipole moment, polar

two atoms bound by a polar bond must have a ..........., and therefore be polar

sigma bonds

end-to-end overlap of orbitals from the two bonded atoms

pi bonds

when several end-to-end overlaps of orbitals exists.

single bond

one sigma bond

double bond

a sigma bond and a pi bond

a triple bond

a sigma bond and two pi bonds