Structure and bonding

Question 1

What are the 3 types of bonds

Answer 1

Metallic bonds
Ionic bonds
Covalent bonds

Question 2

What type of bonds do metals and non metals form?
What bond is formed if there is a mix of the 2?

Answer 2

Metals form metallic bonds
Non metals form covalent bonds
A mixture of metals and non metals form ionic bonds

Question 3

Describe metallic bonding

Answer 3

The type of chemical bonding that arises from strong electrostatic forces between delocalised electrons and positively charged ions

Question 4

Describe the properties of metals

Answer 4

They conduct electricity (delocalised electrons are free to carry a charge)
Conduct thermal energy
High melting points
Malleable

Question 5

Properties of alloys

Answer 5

Alloys are a mixture
Atoms are different sizes
Layers cannot slide, since they are distorted
This makes an alloy harder

Question 6

Describe ionic bonding

Answer 6

Transfer of electrons from a metal to a non metal
Forms charged particles (ions)

Question 7

, How man electrons do groups 1, 2, 6 and 7 lose / gain?

Answer 7

Group loses 1 electron
Group 2 loses 2 electrons
Group 6 gains 2 electrons
Group 7 gains 1 electron

Question 8

Describe ionic compounds

Answer 8

Giant ionic lattice
Positively and negatively charged ions are in a constant ratio
Strong electrostatic force of attraction in all directions
Solid at room temp
Conduct electricity when molten or aqueous

Question 9

Describe covalent bonds

Answer 9

Non metals
Shared pairs of electrons
Giant covalent structures

Question 10

What are small covalent molecules?

Answer 10

Structures which contain a few atoms covalently bonded together
Only weak intermolecular forces between the molecules
Larger molecules have higher melting and boiling points
Cannot conduct electricity

Usually contained in gases or liquids that have low melting or boiling points

Question 11

Oxygen contains a ____ bond and nitrogen contains a ______ bond.

Answer 11

double, triple

Question 12

The melting or boiling point of a substance is determined by the ____.

Answer 12

Amount of energy required to overcome the forces between the particles

Question 13

What are polymers

Answer 13

A very long chain of repeating units called monomers
Monomers are joined via strong covalent bonds
Weak intermolecular forces between polymer strands (still since there are 1000s)
Solids at room temp

Question 14

Three examples of giant covalent structures

Answer 14

Diamond
Graphite
Silica

Question 15

What are giant covalent structures

Answer 15

100s of 1000s of atoms joined by strong covalent bonds

Solids
High melting points

Question 16

Describe diamond

Answer 16

Made of carbon atoms
Every carbon atom makes 4 strong covalent bonds to 4 other carbon atoms
Very hard
High melting point

Question 17

Describe graphite

Answer 17

Made of carbon atoms
Every carbon atom makes 3 strong covalent bonds
Has 1 delocalised electron (can conduct electricity)
Comprised of sheets made of hexagons, with no bonds between the sheets
Very slippery
Useful as a lubricant

Question 18

What is graphene

Answer 18

A single layer of graphite

Question 19

What is silica

Answer 19

Made of silicon and oxygen
High melting point
Very hard
Strong
Alot of strong covalent bonds

Question 20

What is a fullerene?
Give 2 examples.

Answer 20

Made from carbon
Made of hexagons
Hollow shapes
(sometimes pentagons of heptagons)
Buckminsterfullerene(C60)
Carbon nanotubes

Question 21

Facts about carbon nanotubes

Answer 21

High length to diameter ratio
Useful in nanotech, electronics and material science.

Question 22

What is a nanoparticle

Answer 22

1-100nm (“a few hundred atoms”)
Smaller then fine particles
High surface area: volume ratio
Different properties when compared to the same substance in bulk