Topic 2; Bonding, Structure And The Properties Of Matter Flashcards
What is ionic bonding?
Electrostatic attraction between positive and negative ions
How are ionic compounds held together?
Giant lattice
Regular structure
Electrostatic attraction between + and - holds structure together
State properties of ionic substances
High MP and BP
Don’t conduct electricity when solid
Conduct when molten or dissolved
What is important when working out a formula of an ionic compound?
Electrically neutral
Positive and negative charges balance each other
How are ionic compounds formed?
Metal and non metal
Electron transfer occurs
Full outer shell
End ions are charged
What is a covalent bond?
Shared pair of electrons between 2 atoms
Describe structure and properties of simple molecular covalent substances
Don’t conduct electricity
Small molecules
Weak intermolecular forces
Low MP and BP
How do intermolecular forces change as size of molecule increases?
They increase
Causes MP and BP to increase as well (need more energy to overcome forces)
What are polymers?
Very large molecules with atoms linked by covalent bonds
What are giant covalent substances?
Solids- covalently bonded atoms in giant lattice High MP and BP Strong bonds Don’t conduct electricity Diamond, graphite
Describe diamond
Four strong covalent bonds for each carbon atom
Very hard
Very high MP
Doesn’t conduct
Describe graphite
3 covalent bonds for each carbon atom Layers of hexagonal rings High melting point Layers free to slide 1 delocalised electrons per carbon atom
Describe fullerenes
Hollow shaped molecules
C60 has a spherical shape - simple molecular structure
Based on hexagonal rings
What is metallic bonding?
Forces of attraction between delocalised electrons and nuclei of metal ions
Describe properties of metals
High MP and BP
Good conductors
Malleable
