Covalent Bonding Flashcards
Covalent bond:
a chemical bond formed by the sharing of e- btwn two atoms (non and non)
molecule:
a neutral group of atoms that are held together by covalent bonds
molecular compound:
a chemical compound whose simplest units are molecules
chemical formula:
shows the type/ # of atoms in the smallest representative unit of a compound
formula unit:
the simplest whole # ratio of ions in an ionic compound
molecular formula:
shows the types/ # of atoms combined in a single molecule of a molecular compound
Intramolecular forces:
occur between atoms
Intermolecular forces:
occur between molecules
Intermolecular forces are not discussed in ionic bonding bc…
there are no molecules
The strength of intermolecular forces will affect the properties of:
covalent compounds such as melting and boiling points
which one is stronger: intra or intermolecular?
INTRAmolecular forces are much stronger
A covalent bond is formed when:
two forces balance (cancel out) at the precise distance where potential energy is at a minimum
molecular orbital:
shared e- orbital
Lowering potential energy =
stability
Most atoms have lower potential energy when they are ________than they have as an_____
bonded to other atoms than they have as an independent atom
A bond forms when atoms are…
a certain distance from each other
bond length:
the distance between two bonded atoms at their minimum potential energy
bond energy:
the energy required to break a chemical bond
Forming bonds atoms –>
releases energy
breaking bonds –>
requires (takes) Energy
When forming bonds, atoms ________ energy. What amount of energy must be needed to break the bonded atoms?
release energy and need the same amnt
The shorter the bond length:
the more energy required to break it
Double bonds/ triple bonds are :
stronger (more energy required to break the bonds)
The octet Rule:
covalent compounds from bonds by sharing e- so each atom has outer energy level with 8 e-
shared e-:
form overlapping orbitals so that each atom achieves a noble gas configuration
Diatomic elements:
most stable in pairs and not found as single atom in nature
Exceptions to the octet rule:
- atoms that cant fit 8 e- & atoms w/ more than 8 e-
ex. hydrogen
boron
main-group elements in period 3 and below
Lewis structure:
H-H or :C-C:
Resonance:
when a single Lewis structure does not clearly represent a covalently bonded molecule or ion
O=S-O <-> O-S=O
Bond characteristics:
-dont conduct electricity (no ions)
- no partially charged poles (ends)
-low melting/boiling points (bc of weak bonds)
- attraction of polar ends form weak intermolecular forces
- e- orbital overlap = molecular oribtals
-polar covaent -> soulable in water
-nonpolar-> is not
