Bonding Flashcards
(20 cards)
Ions are formed by?
An atom losing or gaining an e-
Ionic bond
An ionic bond is formed between 1 non-metal and one metal atom.
Electrostatic attraction occurs between 2 oppositely charged ions to form an ionic bond.
Sodium ion + chloride ion=
Sodium chloride is ionicly bonded together due to electrostatic attraction between the + ion of sodium and the - ion of the non-metal chloride ion
How do u represent an ionic bond ?
In a dot and cross diagram !
Physically, properties of ionic bonds
High meltong points
Hard
Brittle
Cannot conduct electricity unless when molten or dissolved, not when solid
Why are ioncally bonded compounds hard
Strong 3D ionic lattice structure has many strong ionic bonds, which require a lot of energy to overcome
Why do ionic compounds have high mp’s
Have many strong ionic bonds, which are held together by electrostatic attraction forces between oppositely charged ions, require a lot of energy to overcome the electrostatic forces of attraction.
Why are ionic compounds brittle
Bonds are directional. If a force is applied to a layer, it shifts.
The same charged ions will move and meet and repel.
Also, it has different size atoms, so they can not slide so brittle and not flexible and will snap
Why can ionic compounds conduct electricity in molten or dissolved form but not solid
Solid ions are not free to move, and so can carry charge within the giant ionic lattice structure.
In molten and dissolved, they are free and so can carry charge within the giant ionic lattice structure.
Structure of ionic compounds
Ions arranged in a giant 3D structure called a giant ionic lattice structure. The ions held together by strong electrostatic forces of attraction between the opposite charged ions. Many strong ionic bonds form.
Covalent bonding
A shared pair of electrons between two non-metal atoms.
E.g H20 and CH4 - methane
Covalent bonding simple molecular physical properties
Low mp and BP
Cannot conduct electricity
Weak strength
Why are simple molecular covalent compounds weak
Have weak intermolecular forces/van der waals forces in between layers. Don’t require a lot of energy to overcome
Why do simple molecular compounds have low mp and bp
Have weak IM’s /VDW forces in between layers that don’t require a lot of energy to overcome.
Why do simple molecular compounds not conduct electricity
They have no overall charge because they don’t have ions or delocalised electrons to carry around charge
Giant covalent structures types
Need to do ? Buck minister
Graphite, graphene, silicon dioxide, diamond, Buckminster fullerine (altho this is also fullerine)
