Chemical Bonding Chapter 4 Flashcards
What does VSEPR stand for
Valence Shell Electron Pair Repulsion Theory
A region of space in which there is a high probability of finding an electron
Orbital
What is the shape of the p orbital?
Dumbbell
What is the shape of the s orbital?
Sphere
What is the shape of the d orbital
“Four-leaf Clover”
What is the most electronegative element
Fluorine
What is the least electronegative element
Francium
-They are three-dimensional
-They can contain a maximum of two electrons
-Their shapes are predicted by Schrodinger’s equation
Orbital
Substances that are non-conductors and soluble in water
(if not too large)
Molecular Crystals
A substance is a solid that is ductile and malleable and conducts electricity and heat in the solid state.
Metal
Dissolves in water and conducts electricity when dissolved or in the molten state
Ionic Substance
According to VSEPR theory, molecules adjust their shapes to keep what as far apart as possible?
Pairs of valence electron orbitals
A partial positive charge at one end of a molecule combined with a partial negative charge at the other end of a molecule
Dipole
What causes high surface tension in water?
Hydrogen Bonding
Must have this in order to form double and triple bonds
p-orbital
Bond type in double and triple bonds only
pi-bond
Uneven sharing of electrons
Polar Bond
A combination of at least two different orbitals
Hybrid Orbital
3-D arrangement of covalent bonds between atoms
Covalent Network
Weak forces between all molecules
London Dispersion Forces
Attraction associated with the transfer of electrons
Ionic Bond
Attraction between polar molecules
Dipole-Dipole Force
Any force occurring between molecules
Intermolecular Forces
Forces that hold atoms together
Intramolecular Forces
A regular repeating pattern of atoms, ions, or molecules
Crystal Lattice
If the electronegativity difference is 0 to 0.4 inclusive
Nonpolar Covalent
If the electronegativity difference is >0.4 to 1.7 inclusive
Polar Covalent
if the electronegativity difference is >1.7 to 4.0 inclusive
Ionic
How do you find the bond polarity?
Calculate the electronegativity difference between a bond of a molecule
How do you find the polarity of a molecule?
Step 1: find the EN difference between each bond
Step 2: does the molecule have only non-polar bonds if so then the molecule is non-polar. If the molecule has polar bonds move to next step
Step 3: If the molecule is diatomic(1 bond)then the molecule is polar. If the molecule is polyatomic( more than 1 bond) then move on to step 4
Step 4: If the shape of the molecule is not symmetrical then the molecule is polar. If the shape of the molecule is symmetrical move to step 5
Step 5: if the molecules bonded to the central atom are not the same then the molecule is polar. If the molecules bonded to the central are the same the molecule is non-polar
Ionic Crystals properties?
-positive metal and nonmetal ions
-primary force of attraction is ionic bonds through electrostatic forces
-High boiling and melting points
-Conducts electricity when liquid(molten) or dissolved in solution
-Does not conduct as a solid
-Hard Brittle Solid
-Transfer of electrons is necessary to be formed
Examples: NaCl MgO CaCO3
Metallic Crystals properties?
-Closely packed metal atoms
-Mettalix bonding through electrostatic interactions of free moving electrons
-Boiling and melting point varies from low to high (mercury and tungsten)
- Good conductor of both heat energy and electricity when solid
-Sheen: silver and shiny, Malleability & Hardness: Gold is soft and Al is hard
-the condition necessary to form is the “electron sea theory”
Examples: Au, Al, Cu
What causes Metallic Crystals to have properties?
-Sheen: Mobile valence electrons absorb and emit light energy of many wavelengths of light
-Malleability: The “electron sea” allows atoms to slide over each other.
Electrical conductivity: Mobile valence electrons produce an electric current when a metal is connected to a battery
-Hardness: The “electron sea” surrounding the positive nuclei produces strong electrostatic attractions that hold the nuclei together.
Molecular Crystal properties?
-molecules create the crystals
-Inter molecular forces such as h-bonding, dipole-dipole and LDF are the primary force of attraction
-Lower melting points than ionic crystals as IMF are weaker than ionic bonds
-Does not conduct well as solid or when dissolved in a solution
-Softer than ionic crystals
-composed of neutral molecules in order to form
Examples: Ice, Dry Ice, Iodine
Covalent Network Crystal properties?
-Atoms are involved in creating this crystal
-Covalent bonds between the atoms is primary force of attraction
-High melting point because of the strong covalent bonds
- Does not conduct electricity well as the electrons are unable to move freely. They are also insoluble so can’t dissolve in solutions
- Extreme Hardness
-Has a interlocking network structure which allows it to form
-Examples: Diamond, C
What does the polarity of a molecule define?
-surface tension
-melting and boiling point temperatures
-solubility in certain solvents.
How do Polar molecules interact?
Polar molecules interact through intermolecular forces such as hydrogen bonding or dipole-dipole bonding.
