Unit 2: Bonding/IM forces Flashcards
What happens during ionic bonding
Ionic bonding is typically between metals and non-metals, a large difference in electronegativity, where they transfer valance electrons to form a complete outer shell, resulting in an electrostatic bond
What happens during covalent bonding?
Covalent bonding is typically between non-metals and non-metals where there is a smaller difference in electronegativity. They share valance electrons to gain a full outer shell.
What is a metallic bond
There are positive metal ions in a sea of delocalised free electrons
What are dative/ coordinate covalent bonds
When an atom shares two electrons in a bond (represented by an arrow)
What are the properties of ionic bonds
They are soluble since ions are attracted to the delta charges of water. aqueous solutions
They conduct electricity when dissolved or molten due to ions. Can’t in giant crystal state due to tightly packed ions
they have high MP due tp strong electrostatic forces
What are the properties of covalent bonds
Giant covalent
High MP due to many strong bonds to overcome
Graphene can conduct electricity- carbon makes 3 bonds 1 delocalised electron
Molecular covalent
Low MP due to weak VDW
Iodine solid but the rest tend to be liquid or gas
What are the properties of metallic bonds
High MP due to strong electrostatic forces- more electrons donated to the sea, the stronger the forces
Good conductor of electricity- delocalised electorns
What is electronegativity
The tendency for an atom to attract bonding electrons
Electronegativity and covalent bonds- polarity
Hydrocarbons, bonds with the same/similar atoms, and symmetrical molecules are considered non-polar
What are Van der waals
Induced dipole dipole- forces between atoms/molecules that have electrons. As the electrons cloud moves delta positive/negative regions appear forming attraction. the strength of VDW is influenced by the size of the electron cloud
Permanent dipole dipole
the polarity of the molecule results in attractions of oppositely charged ends of molecules creating a stronger force than VDW- influenced by electronegativity
Hydrogen bonding
A type of dipole dipole bonding where hydrogen forms bonds between lone pairs of 3 of the most electronegative elements N,O,F
Hydrogen bonds are strong intermolecular forces created when a hydrogen atom bonded to an electronegative atom approaches a nearby electronegative atom.
Greater electronegativity of the hydrogen bond acceptor will lead to an increase in hydrogen-bond strength.
