2.2.2 Covalent Bonding Flashcards
what structure does covalent bonding form
It forms either simple molecules or giant structures
explain covalent bonding
can omit structure
Occurs between non-metals where they share electrons. It deals with intermolecular forces and strong covalent bonds.
structure would be simple molecules or giant structures
define strong covalent bonds in covalent bonding
Strong covalent bonds are formed from the strong electrostatic attraction between the shared pair of electrons and the nuclei of the bonded atoms
Define dative covalent bonds
both electrons in a covalent bond are donated by the same atom
how do acids and bases interact with dative covalent bonding
Acids are H+ donors and bases are H+ acceptors
how are dative covalent bonds displayed in dot and cross diagrams
both electon symbols are the same eg. NH4+ if N was x and H was . then the H+ ion would be connected to the nitrogen by 2 x’s
how are dative covalent bonds displayed in 3D structures
the dative bond is shown differently than the other bonds which are portrayed as lines. The dative bond displays the 2 donated electrons and then has an arrow from these (the H+ donor) to the H+ acceptor.
In reality you cannot distinguish between dative bonds and covalent bonds
how does covalent bonding differ from other bonding
talk about electrons not types
it has some exceptions to the octet rule
eg. Beryllium, Boron and period 3 onwards
How do beryllium and boron break the octet rule
They each only have 3 outer electrons so can only make 3 covalent bonds. Therefore this is exactly what they do and end up with 6 outer electrons.
eg BF3
BF4 can exist but it uses dative covalent bonding and it is a - ion
how does period 3 onward break the octet rule
From period 3 onward groups 5-8 can make molecules which have more than 8 electrons in their outershell.
Their only rule is that the electrons must be paired.
