bonding, structure, properties of matter Flashcards
what are ionic bonds
two ions (metal and non metal) have opposite charges and therefore are attracted to each other by electrostatic forces. these created ionic compounds
- the transfer of electrons
what is the structure of an ionic compound and how are these presented
3D lattice structure because each ion is attracted to all those around it
ball and stick diagrams
what are the properties of ionic compounds
high melting and boiling points
conductors of electricity
why are high melting and boiling points required for breaking ionic compounds
high melting and boiling points - determined by the strength of the bonds. because there is loads of ionic bonds, a lot of energy is required to break these. therefore needing a high temperature
what form do ionic compounds need to be in, in order to conduct electricity and why
conducts electricity when melted or disolved in water
when in solid form, all particles are fixed and therefore when melted or in liquid, ions are free to move. this movement of charged particles conduct electricity
what is the formular for the ionic compounds:
- hydroxide ions
- sulphate ions
- nitrate ions
- carbonate ions
- aluminium ions
hydroxide ions = OH-
sulphate = SO-2
nitrate = NO3-
carbonate = CO3 -2
aluminium = NH4 +
what are covalent bonds
- sharing of electrons between non metals
when both metals are missing electrons and therefore create a bond to share meaning they both have a full outer shell
what diagrams do you use for covalent bonds
dot and cross OR displayed formular. for a displayed formular you place a line where there was a covalent bond
what type of substances do covalent bonds make
- simple molecular substances such as chlorine
-methane, water - larger structures such as polymers and giant covalent structures
what is metallic bonding
bonding between metals
- giant structure of metal atoms are arranged in a regular pattern. they share their outer shell of electrons meaning they become positive ions. there will be strong electrostatic attractions meaning metals are held together making it strong
what are properties of metallic bonding
- very strong
- high melting and boiling point
- good conductors of electricity and heat because of delocalised electrons
- malleable because of the regular structure, layers slide over each other
what are delocalised electrons
Bonding electrons that are no longer associated with any particular atom. electrons that are free to move
what are alloys
metallic bonds that contain two or more different elements. two different metals or non metals with different sized atoms
why do the two different elements need different sized atoms
disrupts the regular structure and layers can no longer slide over each other making them much harder than pure metal.
what is an example of an alloy and where is it used
steel, this is used in cars/ planes
what are the three states of mater and explain the properties and how they change between states
solid - strong forces of attraction meaning the particles are held together. this means there is a definite shape or volume
liquid - adding heat to solid meaning particles gain more energy causing them to vibrate breaking the bonds. weak forces of attraction meaning the particles are free to move
gas - more heat added, particles gain more energy weakening force holding particles. once at boiling point, particles will be able to break bonds all together. liquid evaporates to gas.
what are the positives and negatives of the particle model
negatives - particles aren’t actually solid, inelastic or sphered shape
- doesn’t include details of the forces between particles such as how strong
positives - it is a useful simplification to allow understanding of the complicated concept
what are state symbols for each state of matter
solid (s), liquid (l), gas (g), aqueous (aq) - disolved in water
how can you predict what state something is when given an exam question with information
use an increasing temperature timeline
what are polymers
chain of molecules, each polymer molecules is made up of smaller units called monomers
how do you know that a molecule is a polymer
identify the repeating monomer
use the monomer polypropene and identify the repeating monomer
H CH3 H CH3 H CH3 H
| | | | | | |
H - c - c - c - c - c - c - c - H
| | | | | | |
H H H H H H H
H CH3
| |
(- C - C -) n
| |
H H
describe a polymers melting and boiling point
polymers intermolecular forces are quite weak ( weaker than covenant and iconic) yet because polymers have a large surface area, melting and boiling points a pretty high
what are simple molecular substances
small molecules made up of a few covalently bonded atoms with weak intermolecular forces
