why are covalent bonds formed
when non metals react it is more energetically favourable to share electrons and form compounds/ molecules rather than become ions
what diagrams are used to demonstrate covalent bonding
dot and cross diagrams
what are the different pairs involved in covalent bonding called
lone pairs and bonding pairs
what is dative covalent bonding
when a pair of electrons in a bonding pair are transferred from the same element
how are the shapes of covalently bonded molecules decided
by number of bonding electrons and electron pair repulsion theory
how does the electron pair repulsion theory shape molecules
similar charges repel so electrons arrange themselves as far from eachother as possible.
what is formed when 4 groups of electrons surround a central atom (single bonds)
a tetrahedral shape with angles of around 109.5 between each electron pair
where can repulsion happen in bonding pairs
between lone and bonding pairs or individual respective pairs
why do lone pairs repel more strongly than bonding pairs
electrons involved in bonding are being shared by two nuclei and therefore their negative charge would be spread out
bond angle and example of 4 single covalent bonds
Methane- 109.5 forms a tetrahedral shape
bond angle and example of 3 single covalent and one lone pair
ammonia- 107 forms a trigonal pyramidal shape
bond angle and example of 2 single covalent and 2 lone pairs
water- 104.5 forms a v shape
what is a linear molecule
has a total of 2 electron groups. A molecule with bond angles of 180 degrees
Cl-Be-Cl
why is it that the fewer the electron groups the bigger the angle is
The electrons can get further apart and because there is more space the angles become larger.
what is a trigonal planar molecule
a molecules with 3 groups of electrons surrounding a central one with bond angles of 120 degrees
what is a bypiramidal molecule
5 groups of electrons around a central atom. Electrons are at 5 corners of the shape. Angles are either 120 or 90 depending on position
what ifluences the bond angles the most
the number of lone pairs and bonding pairs.
what is an octahedral molecule
six groups of electrons around a central atom. 90 degree angles between pairs of electrons
