C2 - Structure and Bonding Flashcards
Ionic bonding occurs when ____ are combined with _____.
metals, non-metals
(either order)
Define ions
Ions are charged atoms that have lost or gained electrons to gain a full outer shell
Do non-metals lose or gain electrons to form ions?
They gain electrons (to form negative ions)
Do metals lose or gain electrons to form ions?
They lose electrons (to form positive ions)
Give three properties of ionic compounds and describe why they are that way
High melting/boiling points
-strong electrostatic force of attraction so it requires a lot of energy to break
Soluble
-ions can move THROUGH THE STRUCTURE
Conducts electricity when molten or in solution
-ions are free to move THROUGH THE STRUCTURE
Define covalent bonding
sharing a pair of electrons
Covalent bonding occurs when ____ are combined with _____.
non-metals, non-metals
Why do covalent compounds have low melting/boiling points?
The intermolecular forces between molecules are weak.
Give some properties of a diamond lattice
Rigid structure, each atom forms 4 bonds, very hard and high melting point(strong covalent bonds - needs lots of energy to break), can’t conduct electricity (no free electrons)
Give some properties of a graphite lattice
layers, each atom forms 3 bonds, soft (layers slip and slide), high melting point (strong covalent bonds), can conduct electricity (has free electrons)
Give some properties of a graphene lattice
single layer, transparent, very strong, good conductor of electricity (free electrons)
What element are all giant covalent lattices made out of?
Carbon
Define polymer
a long chain made of monomers
Define monomer
small molecule that make up a polymer
Name some uses of nanoparticles:
nanomedicine, cosmetics, electronics
nanoparticles have a very high _____________, making them _______.
surface area to volume ratio, hollow
Metallic bonding occurs when ____ are combined with _____.
metals, metals
Give 3 properties of metals and explain why they are like that
High m/b point
-strong electrostatic force of attraction between +metal ions and -electrons
Good conductor
-free electrons can flow THROUGH THE STRUCTURE
Malleable when heated
-layers can slip and slide
Define an alloy
A mixture containing a metal
Give three properties of metals and describe how they’re different in alloys
-m/b point is lower because bonds between atoms are weaker
-conductivity is decreased because electrons flow less easily THROUGH THE STRUCTURE
-less malleable because layers are distorted so it’s harder to slip and slide
Describe metallic bonding (describe diagram)
layers of positive metal ions surrounded by a sea of delocalised electrons
