Ionic, Covalent and Metallic Bonding

Question 1

What is ionic bonding?

Answer 1

GIANT IONIC LATTICE.

occurs between a metal and non-metal.
it is the electrostatic attraction between oppositely charged ions in a lattice.

e.g sulfate (SO2-), hydroxide (OH-), nitrate (NO3-), carbonate (CO3^2-), ammonium (NH4+)

Question 2

State and explain the properties of ionic structures? eg sodium chloride

Answer 2

• high melting and boiling points bc the electrostatic forces holding the ionic lattice together are strong therefore needs a lot of energy to overcome the bonds.
• when molten OR in solution (aq), ionic substances can conduct electricity bc there are free/mobile ions. they can freely move and carry the flow of charge.
• they are brittle - when the layers of charges are distorted, the like charges repel, therefore breaking apart the lattice into fragments.

Question 3

What is covalent bonding?

Answer 3

between two non-metals.
they share electrons in order to have a full outer shell.

eg iodine (SCM)

Question 4

What is dative covalent bonding?

Answer 4

when both of the electrons in the shared pair are from a single atom.
use an arrow from the lone electron pair to indicate dative bonding.

Question 5

What is metallic bonding?

Answer 5

involves attraction between delocalised electrons and positive ions arranged in a lattice.

Question 6

What affects the forces of attraction in metallic bonding?

Answer 6

• the greater the charge on the positive ion, the stronger the FoA as more electrons are released into the “sea” of delocalised electrons.
• larger ion produces a weaker FoA bc of the greater atomic radius eg. Barium.

Question 7

What are the properties of metallic structures? eg magnesium

Answer 7

• high melting and boiling points bc the electrostatic FoA between the positive ions and delocalised electrons are very strong therefore need a lot of energy to overcome.
• good conductors of electricity bc the “sea” of electrons can move and carry a flow of charge.
• malleable bc the layers of positive ions can slide over each other.

**mercury is the only liquid metal at room temperature - the rest are solids.

Question 8

What are the properties of simple molecular structures eg Iodine?

Answer 8

SCM are covalently bonded molecules held together by weak van der waals forces.

-low melting and boiling points bc van der waals forces are very weak therefore not much energy needed to overcome them.
*however water has a high melting/boiling point bc it has hydrogen bonding.

• poor conductors bc it has no charged particles or free mobile ions.

Question 9

What are the properties of macromolecular structures like diamond? (GCL)

Answer 9

• high melting point bc it has multiple covalent bonds
• rigid because one carbon atom is bonded to 4 other carbon atoms

Question 10

What are the properties of macromolecular structures like graphite? (GCL)

Answer 10

each carbon atom is bonded to 3 others in flat sheets.
the free electrons can move between the layers, so it can conduct electricity.

Question 11

Everything about ice.

Answer 11

3D hexagonal structure held together by hydrogen bonds.
^ a large space is made between the molecules causing it to expand and become less dense (ice floats).

• high melting point due to strong hydrogen bonding between the molecules

Question 12

EQ: Which statement about inorganic ionic compounds is always correct?

Answer 12

Answer: D

Question 13

EQ: In which substance do covalent bonds break when it melts?

Answer 13

Answer: D

Question 14

EQ: Explain why a fluoride ion is larger than a sodium ion

Answer 14

1. Fluoride ion has (two) fewer protons/lower nuclear charge
2. Weaker attraction between nucleus and (outer) electrons