4.2 - Covalent Bonding Flashcards
What is the definition of covalent bonding?
electrostatic attraction between protons in two nuclei and a shared pair of electrons between them
Covalent bonding is a very strong…
attraction
Why do simple molecular substances have LOW BPs?
-weak intermolecular forces between molecules
-requires little energy to overcome
As molecular mass increases so does…
BOILING POINT - strength of IMF’s increase
Are simple molecular substances conductors?
no, all molecules are neutral - no free moving charge particles
How many carbons make up fullerene?
60
Does fullerene have a high or low molecular mass?
HIGH
What properties does fullerene have?
-electrical insulator
-soft and slippery (molecules can roll over each other easily)
Give 2 examples of giant covalent substances
-diamond
-graphite
How is diamond structured?
-tetrahedral shape
-strong, grid-like arrangement
-each C makes 4 covalent bonds
Why do diamond and graphite sublime at such high temps?
-covalent bonds are very strong
-lots of bonds in giant lattice
-lots of energy required to break all bonds
What is diamond used for?
cutting - hard substance
Can diamond conduct electricity?
no - all atoms are neutral, all electrons stuck inside an atom or bond (not free-moving)
How is graphite structured?
-layers of hexagons of C atoms
-each C make 3 covalent bonds
-weak IMFs between layers
-delocalised electrons inside each layer
What is graphite used for?
solid lubricant, pencils - soft and slippery, layers can slide easily
