States of Matter Flashcards
state the limitations of the particle model of matter
- there are no forces
- all particles are shown as spheres
- the spheres are solids
describe the structure and properties of ionic compounds
- they have regular structures called giant ionic lattices.
- there is strong electrostatic forces of attraction between oppositely charged ions
they have high melting and boiling points - large amounts of energy is needed break the many strong bonds and overcome the electrostatic attraction
they can conduct electricity when molten or dissolved in water - ions are free to move and carry a charge.
describe the structure and properties of small molecules.
they have weak forces between the molecules - these weak forces are overcome when they change state not the strong covalent bonds
low melting and boiling points - small amounts of energy is needed to break the intermolecular forces and most are gases or liquids
do not conduct electricity - particles do not have an overall electric charge
describe the structure and properties of polymers.
they are made up from many small reactive molecules that bond onto each other to form long chains. The atoms in the polymer molecules are linked to other atoms by strong covalent bonds. The intermolecular forces are relatively strong.
solid at room temperature - strong intermolecular forces
describe the structure and properties of giant covalent structures.
all atoms within the structure are linked by strong covalent bonds - these bonds must be broken for a solid to melt or boil
very high melting and boiling points - very large amounts of energy required to break the covalent bonds
do not conduct electricity - particles do not have an overall electric charge
describe the properties of metals and alloys.
the giant structure of atoms with strong metallic bonding gives most metals a high melting and boiling point.
metals are malleable and ductile because the layers of atoms can slide over each other
delocalised electrons in metals enable electricity and heat to pass through the metal easily
explain why alloys are harder than pure metals
the different sized atoms of the metals distort the layers in the structure, making it more difficult from them to slide over each other, and so make the alloys harder than pure metals
describe the properties of diamond
each carbon forms four covalent bonds with other carbon atoms in a giant covalent structure.
diamond is very hard - is it the hardest natural substance, so is often used to make jewellery and cutting tools
high melting and boiling point - a lot of energy is needed to break the covalent bonds
cannot conduct electricity - there are no free electrons or ions to carry a charge.
describe the properties of graphite
carbon forms three covalent bonds with three other carbon atoms, forming layers of hexagonal rings, which have no covalent bonds between the layers.
graphite is soft and slippery - layers can easily slide over each other because the weak forces of attraction between the layers are easily broken : this is why it is used as a lubricant
it conducts electricity - one electron from each carbon atom is delocalised
describe the properties of graphene
this is a single layer of graphite - a layer of interlocking hexagonal rings of carbon atoms: one atoms thick
good conductor of thermal energy and electricity, has very low density and is very strong
has many uses in the electronics industry
