1.4 Bonding Flashcards
What is ionic bonding?
When one atom donates one or more electrons to the other atom resulting in a positive ion and a negative ion.
What is covalent bonding?
When atoms share a pair of electrons to form a single covalent bond. Each atom gives one electron to the bonding pair. If two pairs of electrons are shared, a double bond is formed.
What is a coordinate bond?
A covalent bond but one atom provides both atoms to the shared pair
What is the attraction between an ionic bond?
Electrostatic attraction between two oppisitely charged ions
What is the attraction between an covalent bond?
Strong electrostatic attraction between the shared pair of electrons
What is electronegitivity?
The ability of an atom to attract the bonding electrons in covalent bond.
Which electronegitivity value adopts the slightly negative charge in a bond?
The larger EN value
What is a polar bond?
A bond with a slightly positive and a slightly negitive charge (different EN values)
What makes a bond more polar?
Larger EN differance
What is a non-polar bond?
A bond between two atoms with the same EN value
What bond is formed if the EN differance is < 0.4?
Non-polar covalent bond
What bond is formed if the EN differance is 0.4 - 1.8?
Polar Covalent bond
What bond is formed if the EN differance is > 1.9?
Ionic bond
What are intermolecular forces?
Forces between molecules. These intermolecular forces are much weaker than covalent, ionic or metallic bonds
What are permanent dipole-dipole forces?
When two polar molecules (dipoles) arrange themselves so the negative region of one is close to the positive region of another.
What are dipole-dipole interactions an example of?
Van der Waals forces
How are dipoles formed in non-polar molecules?
due to the constant movement of electrons around the nuclei where sometimes more electrons are concentrated on one side of the atom at any one time, causing a temporary dipole
How does the strength of induced dipole-dipole forces increase?
Increasing the number of electrons
What is the strongest of the intermolecular forces?
Hydrogen bonds
What are hydrogen bonds?
Occur between molecules sharing hydrogen atoms bonded to very small, very electronegative elements which have lone pairs.
What is the nature of boiling points of the Group 4, 5 and 6 Hydrides?
Increase as you go down the group due to stronger Van der Waal’s forces.
What does VSEPR mean?
Valence shell electron pair repulsion
What does the VESPR principle state?
- molecule shape determined by number of electron pairs in outer shell
- All electron pair repel each other so they adopt the furthest point away from each other
- Lone pairs repel more than bonded pairs
What must we figure out first to determine the shape of molecules?
How many bonding pairs and how many lone pairs
What is the name of a molecule with two bonded pairs and no lone pairs? and what is the bond angle?
Linear. Bond angle = 180
What is the name of a molecule with four bonded pairs and no lone pairs? and what is the bond angle?
Tetrahedral. Bond angle = 109.5
What is the name of a molecule with three bonded pairs and no lone pairs? and what is the bond angle?
Trigonal planar. Bond angle = 120
What is the name of a molecule with five bonded pairs and no lone pairs? and what is the bond angle?
Trigonal bipiramidal. Bond angle = 120 and 90
What is the name of a molecule with six bonded pairs and no lone pairs? and what is the bond angle?
Octahedral. Bond angle = 90
What is the name of a molecule with two bonded pairs and two lone pairs? and what is the bond angle?
Angular/Bent. Bond angle = 104.5
What is the name of a molecule with three bonded pairs and one lone pairs? and what is the bond angle?
Pyramidal. Bond angle = 107
