Topic 1: Materials and their Atoms

Question 1

What is matter?

Answer 1

Any substance that has mass and takes up space (volume).

Question 2

What are particles?

Answer 2

Small units of matter that cannot be broken down any further without changing the identity of the particular substance it comprises.

Question 3

What is an atom?

Answer 3

Smallest, most stable unit of matter.

Question 4

What is a molecule?

Answer 4

2 or more atoms of the same/different elements, joined together by a chemical bond that form the smallest identifiable unit into which a pure substance can be divided into and still retain its identity.

Question 5

What is a compound?

Answer 5

Pure substance composed of 2 or more different elements chemically combined in a fixed ratio.

Question 6

What is an element?

Answer 6

Pure substance composed of only 1 type of atom.

Question 7

What are 2 types of properties?

Answer 7

Physical and chemical.

Question 8

What are physical properties?

Answer 8

Properties that can be directly observed without a chemical reaction occurring and only change the physical appearance of a substance (e.g. colour, density, hardness, melting/boiling points).

Question 9

What are 2 types of physical properties?

Answer 9

Intensive and extensive.

Question 10

What are intensive physical properties and when are they useful?

Answer 10

Do not change in proportion to the amount of material (e.g. colour).
Useful in identifying substances and separating mixtures.

Question 11

What are extensive physical properties?

Answer 11

Change in proportion to amount of material (e.g. mass and volume).

Question 12

What is a mixture?

Answer 12

Impure substance composed of 2 or more different elements that are physically combined (not chemically combined).

Question 13

What are 2 types of mixtures?

Answer 13

Homogeneous and heterogeneous.

Question 14

What is a homogeneous mixture?

Answer 14

Mixture in which the composition is uniform throughout the mixture; thoroughly dissolved.

Question 15

What is a heterogeneous mixture?

Answer 15

Mixture in which the composition is not uniform throughout the mixture.

Question 16

What is a solution and what is it composed of?

Answer 16

Homogenous mixture.
Composed of a solute (solid) dissolved in solvent (liquid).

Question 17

Is solubility intensive/extensive?

Answer 17

Intensive; does not change in proportion to amount of material.

Question 18

What is solubility?

Answer 18

Measures amount of a material that can be dissolved in a given liquid at a given temperature.

Question 19

What is thermal energy?

Answer 19

Total kinetic energy of particles within a substance/material. Extensive.

Question 20

What is temperature?

Answer 20

Average kinetic energy of particles within a substance/material. Intensive.

Question 21

What causes the phenomenon of heat?

Answer 21

The constant motion the particles in substances undergo is experienced as heat.

Question 22

What is thermal conductivity?

Answer 22

Measure of the ability of a material to transmit heat through conduction.

Question 23

What is the process of conduction?

Answer 23

When particles, in their normal course of motion due to their thermal energy, collide with other particles, and transfer some of that kinetic energy.

Question 24

What is current electricity?

Answer 24

The motion of electric charge.

Question 25

What is electrical conductivity?

Answer 25

Measure of the ability of a material to carry electricity through the movement of its charged particles.

Question 26

What characterises good electrical conductors?

Answer 26

Charged particles are free to move with little resistance.

Question 27

What are high-resistance conductors?

Answer 27

Substances which can carry electricity, but charged particles encounter more resistance as they do so, causing the material to heat up.

Question 28

What are metal alloys?

Answer 28

Substances that combine more than one metal or mix a metal with other non-metallic elements.

Question 29

What are chemical properties?

Answer 29

Describe the way a material can undergo chemical changes; so, observation requires a chemical reaction to occur.

Question 30

What are nanomaterials?

Answer 30

Substances that contain particles in size range 1-100nm.

Question 31

What is a defining feature of nanomaterials?

Answer 31

Enormous SA:Vol ratio.

Question 32

What are pure substances (2 types)?

Answer 32

Substances composed of one type of particle (e.g. elements and compounds).

Question 33

What is filtration used for?

Answer 33

To separate heterogenous mixtures containing particles in a liquid medium.

Question 34

What is the outcome of filtration?

Answer 34

Separation of the solid and liquid components, which are both retained.

Question 35

What is the purpose of evaporation?

Answer 35

To separate a liquid solvent from one or more solutes using differences in boiling points.

Question 36

Which has the higher boiling point: solvent or solute?

Answer 36

Solute.

Question 37

What is the outcome of evaporation?

Answer 37

Solute(s) are retained but solvent is lost.

Question 38

What is the purpose of distillation (simple)?

Answer 38

To separate a liquid with a low boiling point from other substances.

Question 39

What is the purpose of fractional distillation?

Answer 39

Allows liquids with similar boiling points to be separated.

Question 40

What is the outcome of simple distillation?

Answer 40

The low boiling point liquid is isolated, and the other mixture components are retained.

Question 41

What differentiates fractional distillation from simple distillation?

Answer 41

Use of a fractionating column.

Question 42

What are the 3 subatomic particles?

Answer 42

Proton, neutron, electron.