Ceramics, Polymer, Composites, Endo and Exothermic reactions Flashcards
Porcelain is used for:
cable support for electricity pylons as it does not conduct electricity.
Ceramics are generally:
High m.pt., solids, strong, hard, brittle, durable, non-conductors of heat and electricity, and unreactive.
China is used for:
tableware, as it is strong and heat insulator.
Ceramics are:
a range of hard, durable, nonmetallic materials generally unaffected by heat, eg. china and glass.
Ceramic structure:
Ceramics often have a lattice structure with billions of atoms held together by strong bonds in a rigid grid-like pattern.
How are larger crystals formed?
when molten ceramics are cooled slowly.
Polymer structure:
Polymers are often long chain molecules made up of repeating groups of atom.
What makes polymer harder and less easy to melt?
If cross-links are formed between chains.
Polymer:
generally strong, flexible, non-conductors of heat and electricity, durable and unreactive. A polymer is any of a class of natural or synthetic substances composed of very large molecules, called macromolecules, which are multiples of simpler chemical units called monomers.
What are most synthetic polymers made from?
crude oil.
How are polymers formed?
by joining together many small molecules called monomers.
Exothermic reactions:
They transfer energy to the surroundings so the temperature of the surroundings rises. eg. freezing water into ice, campefire.
Endothermic reactions:
They transfer from the surroundings so the temperature of the surroundings falls. eg. cooking an egg.
Whar composites?
combination of two or more different materials.
Composite structures:
Many composite materials contain fibers embedded in a matrix or resin.
