CHAPTER 4 BONDING CHEM GT

Metallic Bonds

Between two metal atoms

Sea of Electrons

All the valence electrons going from one positive ion to another

Results of Sea of Electrons

Cause metals have high luster, are ductile and \n malleable, and conduct heat and electricity

Alloy

A mixture of metals

Substances with metallic bonding have…

high boiling points, not soluble in water, and a crystal lattice

Metals tend to *__* electrons while Nonmetals tend to __ electrons

Metals tend to lose electrons while Nonmetals tend to gain electrons

Positive ions

Cations

Negative ions

Anions

Columbic attraction

The attraction / repulsion between positive and negative charges

Ionic compounds

The transfer of electrons from a metal to a nonmetal

Ionic compound traits

Solid at room temperature as they have high melting and boiling points, they often are soluble in water and conduct \n electricity when dissolved and as a liquid and they form crystals

The sum of an ionic compound’s charges **MUST** be

ZERO

Covalent Bonds

Also known as Molecular compounds, The sharing of electrons among two or more nonmetal atoms

Covalent Bond Traits

Molecular compounds are generally liquids or gases at room temperature because they have low melting and boiling points. They do not conduct electricity in any state and are often not soluble in water

Nonpolar Covalent

Electronegativity difference: .4 or less

Equal Sharing of e- \n 50% / 50%

Charge: None

Polar covalent

Electronegativity difference: .5-1.7

Unequal Sharing \n 40% / 60% to \n 10% / 90%

Charge: Partial

Ionic (Electronegativity difference)

Electronegativity difference: 1.8 or more

Transfer of e- \n 0% / 100%

Charge: Full

VSEPR Theory

Looks at the outer level of an electron and see how it repels from one another, which determines the shape of the molecule

Linear shape

Angle: 180

Shape: Two atoms or two double bonds

Trigonal Planar shape

Angle: 120

Shape: 3 shared (bonded) pairs and 0 unshared pairs

Tetrahedral shape

Angle: 109.5

Shape: 4 shared (bonded) pairs and 0 unshared pairs

Pyramidal shape

Angle: 107

Shape: 3 shared (bonded) pairs and 1 unshared pair

Bent shape

Angle: 104.5

Shape: 2 shared (bonded) pairs and 2 unshared pairs

Polar and Non-Polar molecules

Polar and Non-Polar bonds are **DIFFERENT** from Polar and Non-Polar molecules. In order to find if a molecule is polar or non polar, we first need to find if their bonds are polar or non polar

Non Polar Molecules

If there bonds are non polar, then they are always non polar molecules.

If the bonds are polar but are __***3 atom linear, trigonal planar, or tetrahedral***__, then they are Non Polar Molecules.

Polar Molecules

If the bonds are polar but are __***2 atom linear, pyramidal, or bent,***__ then they are Polar Molecules.

Intermolecular Forces (IMF)

The bonds **BETWEEN** molecules. IMF is much weaker than any kind of bond (Covalent, Ionic, and Metallic)

The stronger the IMF…

The higher the boiling and melting point

Dipole-Dipole forces

The poles (partial positive and partial negative charges) of a \n polar molecule are attracted to the poles of another polar molecule. Between two polar molecules

Hydrogen ~~Bonds~~

Dipole-Dipole forces that include hydrogen bonded to a __***Nitrogen, Oxygen, or Fluorine*** *(Never On Friday)*__. This is the **STRONGEST** out of the all the IMFs but still the **WEAKEST** out of all the bonds.

London Dispersion Forces

A temporary dipole is one that is not normally present \n (nonpolar molecule), but is created momentarily by a shift of electrons. When this happens to two molecules at the same time, the opposite partial charges attract each other for the few moments that both induced dipole exists

London Dispersion Forces are…

the weakest out of all the IMFs but all molecules will have London Dispersion forces.

Properties of Metallic Bonds:

Solubility in H2O: No

Melting Point: High

Boiling Point: High

States that Conduct Electricity: Solid and Liquid

Properties of Ionic Bonds:

Solubility in H2O: Yes

Melting Point: High

Boiling Point: High

States that Conduct Electricity: Liquid and when dissolved in water

Properties of Covalent Bonds:

Solubility in H2O: NonPolar-no| Polar-yes

Melting Point: Low

Boiling Point: Low

States that Conduct Electricity: None