Structure + Bonding Flashcards
What is an ion?
A charged particle
What consists in an ionic compound?
A metal + non-metal
What happens in ionic bonding?
Non-metals gain electrons to form negative ions
Metals lose electrons to form positive ions
What groups are likely to form ions and what charges do they have?
Group 1 - 1+ ions
Group 2 - 2+ ions
Group 6 - 2- ions
Group 7 - 1- ions
Explain the formation and bonds of ionic compounds:
Oppositely charged ions are in a regular lattice which has strong electrostatic attraction due to it’s oppositely charged ions
Properties of ionic compounds:
High melt + boil point due strong bonds which require a lot of energy to break
Solid at room temp - can’t conduct as ions can’t move
When melted or dissolved in water can conduct
What consists in a covalent bond?
Non-metal atoms
How are covalent bonds formed?
Atoms share electrons to have a full outershell
What are simple molecular substances?
Made of a few atoms joined by covalent bonds
Explain the bonds and intermolecular forces of covalent bonds:
Covalent bonds are strong but intermolecular forces are weak
Properties of covalent bonds:
Low melt + boil point due to weak intermolecular forces which require little energy to break
Molecular substances are liquids/ gases at room temp
Don’t conduct - no free electrons and don’t carry an overall charge
What is the formation of metals?
Built layer upon layer
Very strong electrostatic attraction between ‘a sea’ of delocalised electrons and positive metal ions that hold lattice together
Properties of metals:
Can conduct electricity + thermal energy as electrons can move
High melt + boil point due to strong electrostatic attraction between metal atoms and delocalised electrons requires a lot of energy to break bonds
Malleable as layers can slide over each other
What is an alloy?
A mixture of metals
Why are alloys harder than pure metals?
Regular layers are distorted by atoms of different sizes
