Structure and Properties Flashcards
What hold te ions together in giant structures of ionic compounds
Strong electrostatic forces
Ionic Compounds have what structure
Giant structures
Ionic compounds properties
High melting points and high boiling points as a lot of energy is needed to overcome the ionic bonds
Why do ionic solids have high melting points
As it takes a lot of energy to overcome ionic bonds
Why can ionic substances conduct electricity when molten or when dissolved in water
As ions in structure become free to move so they conduct electricity
What are in molecules
Atoms
What are the atoms in a molecule held together by
Strong covalent bonds
Why do simple molecules have little attraction for each other
As the bonds are only between the atoms within the molecule as they share(caring covalent)
Simple molecule properties
Low melting point low boiling point
Why do simple molecules not conduct electricity
No overall charge so can’t carry electrical charge
Intermolecular forces
Forces of attraction between molecules
Why are substances with large molecules more likely to be liquids or solids at room temp
Strong intermolecular forces stronger attractions
Why do substances with giant covalent structures have very high melting points
As takes a lot of energy to break down the lattice (structure)
Two similarities and two differences between diamond and graphite
Similarities- both a from of carbon both covalently bonded
Differences- diamond seethe ouch graphite grey diamond hard graphite slippery
Fullerenes
Large molecules formed from hexagonal rings of carbon atoms
Diamond and graphite both have high…
Melting points because they are both giant covalent structures
Metal atoms are arranged In
Layers
Why can metals be made into wires
As when force is applies to atoms the layers can slide over each other making the mental bend or stretch without breaking so useful to make wires
Alloys
Mixture of metals or metals mixed with other elements
Why are alloys harder then pure metals
Different sized atoms in the mixture distort the layers in mental structure making it difficult to slide over each other
Shape memory alloys
Alloys that can be bent or deformed into a different shape
Two reasons why alloys can be more useful then pure metals
They are harder and shape memory alloys can be deformed but turn back into original shape when heated
Metal structures have what electrons
Delocalised electrons
Why are metals good conductors of heat and electricity
Delocalised electrons move throughout the giant metallic lattice and can transfer energy quickly
What do properties of polymers depend on
Monomers used to make them, changing reaction conditions
Thermosoftening polymers
Soften or melt easily when heated
Example of thermosoftening polymer
Poly(ethene)
What are thermosoftening polymers made of
Individual polymer chains that are tangled together
Thermosetting polymers
Do not soften or melt when heated
What are thermosetting polymers made of
Strong covalent bonds form cross links between their polymer chains
What is the main difference in the structures if thermosetting and thermosoftening polymers
Setting have strong covalent bonds
Softening have individual polymer chains tangle together
What allows thermosoftening polymers to be remoulded
When polymer cools down the intermolecular forces bring the polymer molecules back together do the polymer hardens again
Nanoscience
Study of small particles that are between 1 and 100 nanometers in size
What is a nano particle
Very small particles containing a few hundred atoms and arranged in a particular way
Nano particles behave..
Differently from the materials they are made from
What can nano particles be used for
Catalysts, new cosmetics, new coatings, to give construction materials special properties
