Chem Bonds Test

ionic bond

A chemical bond resulting from the attraction between oppositely charged ions.

Covalent Bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

What does a larger electronegativity difference mean?

stronger attraction for electrons

What does a smaller electronegativity difference mean?

More equal sharing

Nonpolar Covalent

0.0-0.4

Polar covalent

0.5-1.6

Ionic

1.7 and up

Diatomic Molecule

2 atoms of same element covalently bonded

Explain the potential energy chart of a covalent bond.

Optimal length is lowest potential energy

Bond length

distance between 2 bonded atoms are minimum potential energy

Bond energy

Energy required to break chemical bond

Octet Rule

States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons

exceptions to the octet rule

Hydrogen (2), Beryllium (4), Boron (6), Al (6)

Resonance structures

structures that occur when it is possible to draw two or more valid electron dot structures

Formal Charge Equation

Valence - Nonbonding - (bonding/2)

Formula unit

lowest possible ratio of elements

Crystal Lattice

a three-dimensional geometric arrangement of particles

Lattice Energy

the energy needed to break lattice

Ionic Compound Properties

- strong electrostatic force
- high melting points
- brittle
- conductive in liquid state (mobile ions)

Molecular Compound Properties

- weaker attractive forces
- less brittle
- lower melting & boiling points

Sea of electrons

mobile e- around metal atoms in crystal lattice

Metallic bond

chemical bond formed from electrostatic attraction between metal atoms and sea of electrons

Shiny

when electrons absorb the light they reemit it, causing the metal to appear shiny

Why is metal malleable?

the bonds are planar, making them easier to pull away or push over

Heat of vaporization

energy to break apart metallic bonds & vaporize, usually high

VSEPR

Valence Shell Electron Pair Repulsion

How do we find electron domains?

Count lone pairs, single, double, and triple bonds on CENTRAL atom (each counts as ONE)

2 Domain Geometry

Electron: Linear
Molecular: Linear
180

3 bonding 0 nonbonding

trigonal planar

2 bonding 1 nonbonding

bent

4 bonding 0 nonbonding

tetrahedral, 109.5

3 bonding 1 nonbonding

trigonal pyramidal

2 bonding 2 nonbonding

bent

5 Electron Domains

5 bonding - trigonal bipyramidal

6 Domain Geometry

6 bonding - octahedral