Ionic and covalent bonding Flashcards
What are ionic compunds
Ionic compounds are made up of alternating positive and negative ions, creating very strong forces of attraction, therefore they have a high melting point
What are the properties of ionic compounds
They can conduct electricity but only when molten and the ions are free and able to allow an electric charge to flow (electrolysis)
Brittle- Crystals that will fracture and bend as the layers will jump and slide over each other when a force is applied
Soluble in water- H20 will break up ionic compounds as the water will surround each ion
What are simple molecular compounds (covalent)
They are made up of two non-metal ions
They have weak bonds (low melting points)
Cannot conduct electricity as there are no delocalised electrons or ions.
What is a diamond structure (giant covalent)
A diamond structure is made of carbon atoms attached to 4 other carbon atoms with very strong bond. They are insulators
Can be used for: jewellery or as drill bits
What is a graphite structure (giant covalent)
Carbon atoms attached to 3 other carbon atoms. very strong bonds between atoms so there is a very high melting point, however, bonds between layers are weak so the material is soft. There are delocalised electrons so a current can be transported.
Can be used as a high temperature lubricant or as an electrical conductor e.g as an electrode in electrolysis
What are carbon nano-tubes
Sheets of graphite rolled into tubes, delocalised electrons make them excellent conductors- better than copper and much, much smaller.
Can be used in miniature circuits but it is difficult to get them to form the circuit shape due to their size. They are very stong and can also be used in boat hulls, sport equipment and more
What are fullerenes
Ball shaped molecules made of carbon atoms
Can be used in construction as they can withstand high pressure
Can be used to transport drugs through the bloodstream (potential cancer treatment)
What is graphene
A single layer of carbon atoms ( a single sheet of graphite. IT is very useful as it is:
1- the best electrical conductor known
2-best known conductor of heat
3-strongest material known
Mainly used in microelectronics, paints, computers, smart phones, tvs,
Bonding summary
Covalent- non metals, electrons shared (venn diagram styles)
Ionic- Metals donate electrons to non metals. Metals become positive ions, non metals become negative ions
