Bonding, structures and properties of matter Flashcards
How do substances melt
Energy transfer to the particles causes the attractive forces between the particles to weaken
How do substances evaporate
Chemical bonds in the substances are overcome
Difference between boiling and evaporation
In evaporation particles only leave the substance from the surface
In boling bubbles of gas form throughout the liquid and rise to the surface
A higher attractive force means
Higher melting and boiling point
because more energy is needed to overcome them
Describe particles in a solid
Regular lattice/ pattern
Vibrate around a fixed point
Low amount of kinetic energy
Particles cannot be compressed
Do not fill a container
Describe particles in a liquid
Irregular pattern
Move around
More kinetic energy than solid
Particles cannot be compressed
Particles fill a container from the bottom
Describe particles in gas
Randomly arranged
Particles moves fast and in any direction
Highest amount of kinetic energy
Completely fill a container
Particles can be compressed
Why is the model used to show particles in a solid liquid gas limited
Particles are represented as solid spheres
Particles aren’t always sphereical
Particles like atoms are mostly empty space
Metal ions charge
Positive
In metallic bonding positive metal ions are surrounded by
A sea of negative electrons
What holds metallic bonding together
Electrostatic force between metal ions and electrons
How do alloys make metals harder
The mixture of different metal atoms distorts the regular lattice layers and prevents them from sliding over each other making alloys harder to bend
Ionic bonding is between
Metal and non-metal
What holds ionic bonds together
Electrostatic attraction between oppositely charged ions
Ionic compounds form structures called
Giant lattices
Properties of ionic compounds
High melting point, energy needed to overcome electrostatic bonds
High boiling point
Can’t conduct electricity as ions cannot move around the substance
However can conduct electricity as liquid or solution
Simple covalent properties
Low melting/ boiling points
Weak intermolecular forces
Do not conduct electricity
Describe the diamond giant covalent structure
Each carbon bonded to 4 other carbons
Very strong
Alot of energy needed to break bonds
High melting/boiling point
Does not conduct electricity has no free floating electrons
Describe the silicon dioxide giant covalent structure
Similar to diamond but not bonded to as many particles
Describe the graphite giant covalent structure
Each carbon bonded to 3 other carbons
Arranged hexagonally
Each carbon has 1 delocalised electron that can carry electricity through the substance
Millions of layers on top of each other
Layers are held together by the weak intermolecular forces
Layers can slide over each other because of no covalent bond between the layers
High melting point as there is alot of energy required to break the 3 bonded carbons
Describe the graphene giant covalent structure
Strong due to 3 covalent bonds for every carbon
Conduct electricity due to delocalised electrons
2 Uses of graphene
Added to other materials to make them stronger
Used in electrics and composites
What type of particles have a large SA:V ratio
Nanoparticles
What size is nanoparticles
1-100nm
