Structure 1

Question 1

Matter

Answer 1

Pure substance and mixture

Question 2

Pure substance

Answer 2

Has definite and constant composition
Element
Compound

Question 3

Mixture

Answer 3

A combination of pure substances that retain their individual properties
Homogenous
Heterogenous

Question 4

Element

Answer 4

All atoms have the same number of protons

Question 5

Compound

Answer 5

A fixed ratio of differing atoms

Question 6

Homogenous

Answer 6

Uniform composition

Question 7

Heterogenous

Answer 7

Non-uniform composition

Question 8

Changes of state

Answer 8

Endothermic
Exothermic

Question 9

Endothermic

Answer 9

Heat (kinetic energy) is added - particles move faster

Question 10

Exothermic

Answer 10

Heat (kinetic energy) is removed - particles move slower

Question 11

Solid -> liquid

Answer 11

Melting - vibrate faster

Question 12

Liquid -> gas

Answer 12

Vaporisation - rotate faster

Question 13

Gas heat further

Answer 13

Translate faster

Question 14

Solid -> gas

Answer 14

Sublimation

Question 15

Gas -> solid

Answer 15

Deposition

Question 16

Gas -> liquid

Answer 16

Condensation

Question 17

Liquid -> solid

Answer 17

Freezing

Question 18

Solution

Answer 18

Solute + solvent

Question 19

Methods of separating mixtures

Answer 19

Solvation
Filtration
Crystallisation
Chromatography
Distillation

Question 20

Solvation

Answer 20

Separating particles based on their solubility in different solvents

Question 21

Filtration

Answer 21

Separating particles based on size using a membrane

Question 22

Crystallisation

Answer 22

Separating particles based on their ease of evaporation

Question 23

Chromatography

Answer 23

Separating by the particle’s different affinities for the mobile phase (solvent) or stationary phase (paper)

Question 24

Distillation

Answer 24

Separating particles based on differences in boiling points

Question 25

Atomic notation

Answer 25

Mass number = A Atomic number = Z Chemical symbol = X Charge caused by loss or gain of electrons = ? A····? ···**X** Z

Question 26

Mass number

Answer 26

protons + # neutrons

Question 27

Atomic number

Answer 27

protons

Question 28

Chemical symbol

Answer 28

Based on # protons

Question 29

Proton

Answer 29

(1+)

Question 30

Electron

Answer 30

(1-): 1/1850 mass of proton

Question 31

Neutron

Answer 31

(0): same mass as proton

Question 32

Isotopes

Answer 32

Atoms of the **same** element with **differing** numbers of neutrons **Different** *physical* properties **Same** *chemical* properties

Question 33

Relative atomic mass

Answer 33

The weighted average mass of the atom, Ar compared to the most common isotope of carbon which has a mass of 12 Ar = x% × A₁ + y% × A₂ + z% × A₃ ...

Question 34

Emission Spectra

Answer 34

Spectrum of coloured light when white light passes through a prism

Question 35

Visible light

Answer 35

400-700 nm (×10⁻⁹ m)

Question 36

Violet light

Answer 36

High wavelength - high energy

Question 37

Red light

Answer 37

Low wavelength - low energy

Question 38

C = f × λ

Answer 38

C = speed of light (constant - 3 ×10⁸ m/s) f = frequency λ = wavelength

Question 39

Absorption spectrum

Answer 39

When light passes through a low energy gas Some bands of light are missing

Question 40

Emission (or line) spectrum

Answer 40

When light passes through a high energy gas Only some bands of light are shown

Question 41

Complementary behaviour of emission and absorption spectra

Answer 41

If the same gas is used, the high energy version's bands would fit the missing bands of the low energy version

Question 42

Bohr's Model

Answer 42

1. electrons exist at discreet energy levels 2. these energy levels get closer together (converge) at higher energies 3. discrete colours are produced when electrons transition to lower energy levels (discrete colours are absorbed when electrons transition to higher level)

Question 43

Energy Level Diagram

Answer 43

1. Aufbau Principle 2. Pauli Exclusion Principle 3. Hund's Rule

Question 44

Aufbau Principle

Answer 44

Electrons fill the lowest energy levels first

Question 45

Pauli Exclusion Principle

Answer 45

An orbital can hold a maximum of two electrons with opposite spin

Question 46

Hund's Rule

Answer 46

One electron in each sublevel with parallel spin before doubling up

Question 47

Electron Configuration

Answer 47

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ ...