C2 Covalent Bonding Flashcards
How are covalent bonds formed?
by sharing electrons
Which type of atoms form covalent bonds between them?
non-metals
describe the structure and bonding of a giant covalent substance
billions of atoms bonded together by strong covalent bonds
properties of simple covalent substances
don’t conduct electricity
low melting and boiling
weak intermolecular forces
what are giant covalent substances
atoms bonded together in a giant lattice
properties of giant covalent substances
high melting and boiling point DUE to it needing lots of energy to break the strong covalent bonds between atoms
3 carbon allotropes
diamond
graphite
silicon dioxide
properties of diamond
~4 strong covalent bonds
for each C atom
~very strong
~very high melting point
~doesn’t conduct electricity
properties of graphite
~3 covalent bonds for each
C atom
~layers of hexagonal rings
~high melting point
~layers free to move / slide
~conduct electricity
Why can graphite conduct electricity?
As there is one delocalised electron per atom meaning that it can carry charge in a sea of delocalised electrons
What carbon fullerene has a spherical shape?
C60
buckminster fullerene
What are intermolecular forces?
forces of attraction that act with neighbouring particles
Why do small molecules have low melting points?
only a small amount of energy is needed to break the weak intermolecular forces
Why do large molecules have higher melting point in comparison to small molecules?
intermolecular forces are stronger in larger molecules
What is a nanotube?
hollow cylinder of carbon atoms
