slop 3 Flashcards
describe the structure of a giant ionic lattice
strong electrostatic forces of attraction between oppositely charged ions acting in all directions
boiling/melting points of IONIC substances
high
why do ionic substances have high melting points
large amounts of energy needed to break the MANY strong BONDS
When can ionic comppounds conduct electricity
when molten or dissolved as the ions will be free to move
state bonding between NON-METALS
Covalent
describe covalent bonding in terms of electrons
SHARING electrons
Do small covalent substances have high or low boiling points
LOW boiling points
Why do small molecules have low melting points?
The weak intermolecular forces are easily overcome by a small amount of energy
State the trend in intermolecular forces as molecules get bigger
as the molecules get bigger, the INTERMOLECULAR forces get stronger
Do small covalent molecules conduct electricity
No, (because no charged particles)
State the type of bonding in metals
Metallic bonding
Describe metallic bonding structure
Strong electrostatic forces of attraction between positive ions and DELOCALISED electrons
State the general melting points of metals
High
State the 4 properties of metals
Malleable, ductile (drawn in to a wire), good connectors of heat and electricity and high melting point
why are metals good conductors of thermal energy
energy is transferred by delocalised electrons
what is an alloy
a mixture of different metals
describe why alloys are harder than pure metals
Layers of atoms are distorted so layers cannot easily slide over each other
why are metals good conductors of electricity
delocalised electrons carry a charge and flow through the metal
which element are diamond, graphite and fullerenes made from
carbon
state the type of bonding between carbon atoms
covalent
how many bonds does each carbon have in a diamond
4
state 4 properties of a DIAMOND
very hard, high melting point, does not conduct electricity and insoluable
how many bonds does each carbon have in GRAPHITE?
3
why is graphene soft
it has weak intermolecular forces between the layers so layers slide over each other
