covalent compounds Flashcards
(13 cards)
covalent bonds are between what metals
between 2 non- metals
what is Covalent bonding
shared pair of electrons between 2 atoms to complete 2 full outer shells
what is 1 limitation of a dot cross diagram
doesn’t show the shape of the molecule
what do simple molecules contain
small number of non- metals joined together by covalent bonds, they have no overall charge so don’t conduct electricity
why do simple molecules have a low melting/boiling point
weak intermolecular forces
explain how molecules can have high melting/boiling points
the larger intermolecular forces, the stronger the intermolecular force, so they would have a high melting/ boiling point
what are the properties of giant covalent structures
-have high melting/boiling point
-don’t conduct electricity as theres no ions
-insoluble in water
Describe the structure of a diamond and the properties
-giant lattice structure
-each carbon atom forms 4 covalent bons
-very high melting point
explain why diamond doesn’t conduct electricity
no charge , no free electrons
Describe the structure of graphite
-giant covalent structure
-each carbon atom forms 3 covalent bonds
-forms layered hexagonal structure
why is graphite slippery and soft
layers are held by weak intermolecular forces that can slide past each other
how does graphite conduct electricity and heat
delocalised electrons can move around and carry their charge
describe the structure of silicon dioxide (silica)
each carbon atom is joined to 2 silicon atom
each silicon atom is joined to 4 oxygen atoms
doesn’t conduct electricity
high melting point
