Changes in State / Bonding Flashcards
what are the properties of a solid?
-they vibrate
-low amount of kinetic energy
-fixed shape
-cannot be compressed
what are the properties of a liquid?
-move around
-greater amount of kinetic energy
-can flow
-cannot be compressed
what are the properties of a gas?
-move around
-very quickly
-highest amount of kinetic energy
-can flow
-far apart
-can be compressed
what is the amount of energy needed for a substance to change state dependent upon?
the strength of the attractive forces
what happens if there are stronger forces of attraction?
more energy is needed to break them apart
what is the ionic equation for lithium?
Li —> Li+ + e-
what is the ionic equation for calcium?
Ca —> Ca2+ + e-
what is the ionic equation for bromine?
Br + e- —> Br-
what is the ionic equation for oxygen?
O + 2e- —> O2-
what does ionic bonding occur between?
a metal and a non-metal
what happens to the electrons with a metal and what does this cause?
metal loses electrons, becoming positively charged
what are opposite charges attracted by?
electrostatic forces
what do ionic compounds form, and what are their properties?
giant lattice - strong electrostatic forces, all directions between oppositely charged ions
what are the key properties of an ionic compound?
-high melting and boiling points
-cannot conduct electricity in solids
-can conduct electricity when molten
what does covalent bonding occur between?
2 non-metals
what happens with the electrons in covalent bonding?
they’re shared to gain a full outer shell
what are the properties of simple covalent structures?
-low melting and boiling points
-weak intermolecular forces
-don’t conduct electricity (no free electrons)
what is metallic bonding and its properties?
-sea of delocalised electrons
-strong electrostatic forces
what are pure metals mixed with and what do they make?
other metals to make alloys
what does making an alloy introduce?
different sized atoms
what does having different sized atoms do to the layers?
it distinct them, preventing them from sliding over each other
what is diamond made up of?
carbon atoms, each bonded to 4 other carbon atoms
what are the properties of diamond?
-strong
-high melting and boiling points
-large amounts of energy to break strong covalent bonds
-doesn’t conduct electricity
what is silicon dioxide made up of?
silicon and oxygen atoms
what are the properties of silicon dioxide?
-strong covalent bonds
-large amounts of energy to break
-high melting and boiling points
what is graphite made up of?
carbon atoms arranged in hexagons, bonded to 3 other carbon atoms, has 1 delocalised electron that can move between layers
what are the properties of graphite?
-layers are held by weak intermolecular forces
-can slide easily
-high melting point
-conducts electricity
what is graphene made up of?
one layer of graphite
what are the properties of graphene?
-strong covalent bonds
-free delocalised electron
-can conduct electricity
what is a fullerene?
molecules of carbon shaped like hollow tubes or balls, arranged in hexagons of 5/7 atoms
what can fullerenes be used to do?
deliver drugs into the body
what is a carbon nanotube?
tiny carbon cylinders that are very long
what are the properties of carbon nanotubes?
-conduct electricity
-strengthen materials
-useful in electronics
why is it possible for nanoparticles to be inhaled?
they’re so small
what happened once nanoparticles are inside the body?
-initiate harmful reactions
-binding to toxic substances
