Physical Chapter 3: Bonding Flashcards
What is a compound?
A molecule made up of different elements bonded together.
What are the two types of bonding in compounds?
Covalent and ionic.
What is an ionic bond?
A bond formed when one or more electrons are transferred from one atom to another.
What holds ionic bonds together?
Electrostatic attraction
What is the formula of a sulfate ion?
SO42-
What is the formula of a hydroxide ion?
OH-
What is the formula of a nitrate ion?
NO3-
What is the formula of a Carbonate ion?
CO32-
What is the formula of an Ammonium ion?
NH4+
What is the overall charge of any compound?
zero
What is the structure of Sodium Chloride?
Giant Ionic Lattice
How does Ionic structure explain coductivity of compounds when dissolved?
Ions in a solid are held in place by strong bonds, whereas they are free to move in liquids.
How does Ionic structure explain high melting point of ionic compounds?
Giant ionic lattices are held together by strong electrostatic forces.
How does Ionic structure explain solubility in water?
Water molecules are polar - these can pull ions away from the lattice, causing dissolution.
What is a covalent bond?
A bond that contains at least one shared pair of electrons.
What is another name for a giant covalent structure?
Macromolecular structure
What is a giant covalent structure?
A molecule made up of a huge network of covalently bonded atoms
What is the structure of graphite?
Sheets of hexagons with delocalised electrons
What are the properties of graphite?
Sheets can slide over each other - it’s a dry lubricant
electrically conductive
Low density - layers are far apart
High melting point - strong covalent bonds
Insoluble - bonds are too strong to break
What is the hardest known substance?
Diamond
What are properties of Diamond?
High Melting Point
It’s very hard
Good thermal conductor
Can’t conduct electricity
Insoluble in all solvents
Refracts light a lot
What is a dative covalent bond?
A bond where both electrons in a pair are donated from one molecule.
What does molecular shape depend on?
Electron pairs around the central atom
What is a charge cloud?
An area where an electron could be - electrons do not stay still
How do Charge clouds interact with each other?
They repel each other, forming the molecule shape
What atom shape will be formed when the central atom has 2 electron pairs?
What is its bond angle?
Linear - 180 degrees
What atom shape will be formed when the central atom has 3 electron pairs?
What is its bond angle?
Trigonal planar - 120 degrees