8.2 - Properties of materials

Question 1

How is the periodic table arranged? [1]

Answer 1

In order of atomic number

Question 2

What is the atomic number of an element? [1]

Answer 2

The number of protons

Question 3

What is the atomic mass of an element? [1]

Answer 3

The number of protons and neutrons

Question 4

What is the charge of protons? [1]

Answer 4

+1 / positive

Question 5

What is the charge on neutrons? [1]

Answer 5

0 / neutral

Question 6

What is the charge on electrons? [1]

Answer 6

-1 / negative

Question 7

Why is an atom neutral? [3]

Answer 7

Same number of positive protons and negative electrons

Question 8

What is the relative mass of protons? [1]

Answer 8

1

Question 9

What is the relative mass of neutrons? [1]

Answer 9

1

Question 10

What is the relative mass of electrons? [1]

Answer 10

1/2000

Question 11

Where are protons found in the atom? [1]

Answer 11

In the nucleus

Question 12

Where are neutrons found in the atom? [1]

Answer 12

In the nucleus

Question 13

Where are electrons found in the atom? [1]

Answer 13

In shells / energy levels

Question 14

What is the maximum number of electrons in the 1st, 2nd and 3rd shells?

Answer 14

1st = 2, 2nd = 8, 3rd = 8

Question 15

How is group number in the periodic table related to electronic structure? [1]

Answer 15

The group number = the number of electrons in the outer shell

Question 16

How is period (row) number in the periodic table related to electronic structure? [1]

Answer 16

The row number = the number of occupied electron shells

Question 17

Define an isotope [2]

Answer 17

Atoms of the same element with the same number of protons and electrons but a different number of neutrons

Question 18

Why do isotopes have the same chemical properties? [1]

Answer 18

Because they have the same number of electrons in their outer shell

Question 19

Describe how metal atoms form ions [2]

Answer 19

Metals lose electrons to form positive ions

Question 20

Describe how non-metal atoms form ions [2]

Answer 20

Non-metals gain electrons to form negative ions

Question 21

Describe an ionic bond [2]

Answer 21

The electrostatic attraction between positive metal ions and negative non-metal ions

Question 22

What type of structure do ionic substances form? [1]

Answer 22

Giant ionic lattice

Question 23

Describe the properties of ionic substances [4]

Answer 23

Low volatility, high solubility, high melting and boiling point, conducts when molten or aqueous

Question 24

Explain the high melting / boiling point of ionic substances [2]

Answer 24

High melting point because of strong electrostatic force of attraction between ions that requires a lot of energy to overcome

Question 25

Explain the electrical conductivity of ionic substances [2]

Answer 25

Able to conduct when molten or aqueous because the ions are free to move and carry charge

Question 26

Describe a covalent bond [1]

Answer 26

A shared pair of electrons between non-metal atoms

Question 26

Describe the properties of covalent substances [4]

Answer 26

High volatility, low solubility, low melting and boiling point, does not conduct electricity

Question 27

Explain the low melting / boiling point of covalent substances [2]

Answer 27

Weak intermolecular forces that require a small amount of energy to overcome

Question 28

Explain why simple covalent substances don't conduct electricity [2]

Answer 28

No free mobile charge carriers (electrons or ions) to carry charge through the structure

Question 29

Name three (covalent) macromolecules [3]

Answer 29

Diamond, graphite, silicon (IV) oxide (silica / silicon dioxide)

Question 30

Describe the structure of diamond [3]

Answer 30

Giant structure, made of carbon atoms, each carbon forms 4 bonds with another carbon

Question 31

Describe the structure of graphite [4]

Answer 31

Giant structure, made of carbon atoms, each carbon forms 3 bonds with another carbon, layered structure

Question 32

Describe the structure of silicon (IV) oxide [2]

Answer 32

Giant structure, one silicon atom for every two oxygen atoms

Question 33

Explain why diamond, graphite and silica have a high melting / boiling point [2]

Answer 33

Lots of strong covalent bonds that require a lot of energy to overcome

Question 34

Explain why graphite is able to conduct electricity [3]

Answer 34

Carbon atoms only form 3 bonds so one valence electron is free and delocalised and can carry charge through the structure

Question 35

Explain why graphite is slippery [2]

Answer 35

Weak intermolecular forces between layers so the layers can slide off each other

Question 36

What is graphite used for? [2]

Answer 36

A lubricant and a conductor

Question 37

What is diamond used for? [1]

Answer 37

Cutting tools