Bonding

Question 1

What is Metallic Bonding?

Answer 1

Metallic bonding is the electrostatic forces of attraction between cations and the electrons that are free to move within the regular lattice structure of a metal.

Question 2

What are 5 properties of Metallic Bonding?

Answer 2

1. Good conductors of heat
2. Malleable and Ductile
3. Good conductors of electricity
4. Metallic lustre
5. High melting/boiling points

Question 3

Why are Metallic Bonds good conductors of heat?

Answer 3

• the small mass of the electrons allows for the kinetic energy to transfer between the particles easier
• the sea of delocalized electrons allows the kinetic energy to be transferred easier through the freely moving electrons
• the density packed cations allow the kinetic energy to be transferred to other cations by vibrations

Question 4

Why are Metallic Bonds malleable and ductile>

Answer 4

• the sea of delocalized electrons move freely meaning that when force is applied, the sea of electrons causes the cations to stay in place

Question 5

Why are Metallic Bonds good conductors of electricity?

Answer 5

• the delocalized electrons are charged and are free to move, therefore carrying the electric current through the lattice structure.

Question 6

Why do Metallic Bonds have metallic lustre?

Answer 6

• the electrons absorb the energy and whilst moving through different energy levels, emit the light back out
• the light cannot pass through their dense lattice structure so the light must rebound back out

Question 7

Why do Metallic Bonds have high melting and boiling points?

Answer 7

• metals have very strong bonds and because of their strong electrostatic forces, it take much more energy to break the bonds

Question 8

What is Ionic Bonding?

Answer 8

Consists of an orderly array of positive and negative ions, the ionic ions are held in the crystal lattice by strong electrostatic attraction to oppositely charged ions.

Question 9

What are 4 properties of Ionic Bonding?

Answer 9

1. Hard and brittle
2. Non-conductors of electricity in the solid state
3. Good conductors when molten or in an aqueous state
4. High melting and boiling points

Question 10

Why are Ionic Bonds hard and brittle?

Answer 10

• the sea of atoms requires a large amount of energy to break
• when force is applied, the structure shifts and causes the ions to align with each other and repel

Question 11

Why are Ionic Bonds non-conductors of electricity in the solid state?

Answer 11

• charged particles cannot flow because the are all fixed in place in the lattice structure and all electrons are in use

Question 12

Why are Ionic Bonds good conductors when molten or in an aqueous state?

Answer 12

• they are more separated so the atoms can move around freely, electrostatic attraction has been broken
• the ions are free from the lattice structure

Question 13

Why do Ionic Bonds have high melting and boiling points?

Answer 13

• due to the strong electrostatic attraction, a lot of energy is required to break the bonds
• the reason why high energy is needed is because a lot of heat energy will break the bond by exciting the particles and allow them to overcome the electrostatic attraction

Question 14

What are Covalent Molecular Substances?

Answer 14

A group of two or more atoms held together by covalent bonds, where electrons are shared between nuclei of atoms.

Question 15

What are 4 properties of Covalent Molecular Substances?

Answer 15

1. Low melting and boiling points
2. Non-conductors of electricity both solid and liquid states
3. Solid which are generally soft and have waxy appearance
4. Tend to be malleable

Question 16

Why do Covalent Molecular Substances have low melting and boiling points?

Answer 16

• the molecules have weak electrostatic attraction, meaning there is less energy required to pull the molecules apart

Question 17

Why are Covalent Molecular Substances non-conductors of electricity in both solid and liquid states?

Answer 17

• the electrons are fixed in position so they cannot move freely to conduct electricity
• the particles have an overall neutral charge meaning there are no free or mobile ions

Question 18

Why are Covalent Molecular Substances solids which are generally soft and have waxy appearances?

Answer 18

• the molecules don’t produce a lattice so they are all separate molecules as the molecular forces/attraction is missing
• they are waxy because there are large gaps between molecules so light can come in
• they cannot reflect light back out because the electrons are fixed in place

Question 19

Why do Covalent Molecular Substances tend to be malleable?

Answer 19

• the forces between molecules are weak so molecules are easily moved relative to each other: this is because there is no crystal lattice structure

Question 20

What are Covalent Network Substances?

Answer 20

Consists of three-dimensional network structures where all atoms are linked by covalent bonds.

Question 21

What are 4 properties of Covalent Network Substances?

Answer 21

1. Very high melting points
2. Non-conductors of electricity in solid and liquid states
3. Extremely hard and brittle solids
4. Insoluble in water and most other solvents

Question 22

Why do Covalent Network Substances have very high melting points?

Answer 22

• the covalent bonds that hold the atoms together are strong

Question 23

Why are Covalent Network Substances non-conductors of electricity in solid and liquid states?

Answer 23

• there are no charged particles that are free to move throughout the structure

Question 24

Why are Covalent Network Substances extremely hard and brittle solids?

Answer 24

• the bonds are very strong between atoms so it’s difficult to scratch, but an impact force disrupts the positions of the atoms and causes the network to shatter

Question 25

Why are Covalent Network Substances insoluble in water and most other solvents?

Answer 25

• there is no attraction between the atoms in the network and water molecules