Chemistry Topic 3 Structure and Bonding

Question 1

What is an ion?

Answer 1

A charged particle formed when atoms lose or gain electrons.

Question 2

What is ionic bonding?

Answer 2

An electrostatic attraction between two oppositely charged ions (metal and non-metal).

Question 3

What is an electrostatic attraction?

Answer 3

The attraction between a negatively charged particle and a positively charged particle.

Question 4

In ionic bonding what do metals do?

Answer 4

In ionic bonding, metals lose electrons to become positively-charged ions.

Question 5

In ionic bonding what do non-metals do?

Answer 5

In ionic bonding, non-metals gain electrons to become negatively-charged ions. Located on the right hand side of the periodic table.

Question 6

What is a giant lattice?

Answer 6

A large regular 3D structure that contains millions of bonds.

Question 7

What is a covalent bond?

Answer 7

A bond formed when non-metals share electrons. An electrostatic attraction between the positively charged nuclei of the bonded atoms and the electrons shared between the.

Question 8

What is a molecule?

Answer 8

A small group of atoms held together with covalent bonds. Not changed.

Question 9

What is a polymer?

Answer 9

A very large covalently bonded molecules with many repeating units.

Question 10

What is metallic bonding?

Answer 10

The bonding of a metal consists of a lattice of positive ions surrounded by a sea of delocalised electrons. The metallic bond is the electrostatic attraction between the positive ions and the delocalised electrons.

Question 11

What is an alloy?

Answer 11

A mixture of two or more elements, at least one of which is metal. E.G. steel is a mixture of ion and carbon.

Question 12

Why do some substances (mainly gases or liquids) have low melting and boiling points?

Answer 12

There are only weak intermolecular forces between the molecules which don’t need much energy to overcome these forces.

Question 13

Why do some substances NOT conduct electricity?

Answer 13

Covalent molecules are not charged and have no free moving electrons.

Question 14

Why might a substance have a high melting/boiling point?

Answer 14

Because it takes lots of energy to overcome the many strong ionic bonds in the lattice. There is a strong electrostatic force between the positive and negative ions in the giant lattice.

Question 15

Why might a substance conduct electricity in a liquid/ molten state?

Answer 15

Ions are able to move so there is a flow of charged ions (current)

Question 16

What do covalent dot diagrams show and not show?

Answer 16

Covalent dot and cross diagrams show which atoms the electrons have come from but don’t show relative size of atoms or their arrangements in space.

Question 17

What are the disadvantages of using silver nanoparticles in fridges and antimicrobial dressings?

Answer 17

Scientists are worries about nanoparticles entering the environment and affecting aquatic life

Question 18

What are the advantages of using silver nanoparticles in fridges and antimicrobial dressings?

Answer 18

They inhibit growth of microogranisms (protects against bacteria)

Question 19

What are the disadvantages of using zinc oxide nanoparticles in sun cream?

Answer 19

Nanoparticles are smaller than skin cells so they can go through the skin and into the bloodstream. This could have unpredictable effects on our cells

Question 20

What are the advantages of using zinc oxide nanoparticles in sun cream?

Answer 20

Nanoparticles are more effective at blocking the suns rays

Question 21

Why might nanoparticles have different properties to regular particles?

Answer 21

Because of their high surface area to volume ratio

Question 22

What is nanoscience?

Answer 22

The study of small particles that are between 1 and 100 nanometres in size

Question 23

Why are alloys harder than pure metals?

Answer 23

Because the different sized atoms distort the layers making it harder for them to slide

Question 24

Why are pure metals malleable?

Answer 24

The layers are able to slide over each other so the metal can be bent and shaped. The attraction between the positive ions and delocalised electrons prevents the metal from shattering

Question 25

Why do pure metals conduct heat?

Answer 25

The delocalised electrons are free to move and transfer thermal energy through the structure

Question 26

Why do pure metals conduct electricity?

Answer 26

The delocalised electrons are free to move and carry a charge

Question 27

Why do pure metals have a high melting point?

Answer 27

Strong electrostatic forces between the positive ions and delocalised electrons require a lot of energy to overcome

Question 28

Name 2 properties of pure metals

Answer 28

• High melting point
• Conducts electricity
• Conducts heat
• Malleable

Question 29

Why are polymers usually solid?

Answer 29

Because the intermolecular forces between polymer molecules are relatively strong

Question 30

Why don’t ionic compounds conducts electricity as a solid?

Answer 30

There are no delocalised electrons so charge cannot flow through

Question 31

Name 2 properties of Graphite

Answer 31

• Conducts electricity

- Soft and slippery

Question 32

Name 3 properties of Diamond

Answer 32

• Doesn’t conduct electricity
• Very hard
• High melting point

Question 33

What is a giant covalent compound?

Answer 33

A compound where all the atoms are bonded via strong covalent bonds in a giant lattice structure