Structure 1.1

Question 1

Pure substance

Answer 1

Made up of only one chemical element or compounds made of two or more elements - has a definite and constant composition

Question 2

Chemical element

Answer 2

A substance that can’t be broken down into simpler substances, consists of atoms containing the same number of protons

Question 3

Compound

Answer 3

A pure substance formed when two or more elements are chemically bonded.

Question 4

Solid (s)

Answer 4

Occupy a fixed space and volume. Particles are held closely together in a lattice.

Question 5

Liquid (l)

Answer 5

Fixed volume that takes the shape of the container. Particles are close together but move randomly.

Question 6

Gas (g)

Answer 6

Completely fills the container, particles are widely spaced and move rapidly and randomly.

Question 7

Heat

Answer 7

A measure of total energy in a substance. Depends on the mass of the substance. Measured in joules

Question 8

Temperature

Answer 8

Measure of average kinetic energy “hotness”. Measured in kelvin (K)

Question 9

When does water boil?

Answer 9

When the vapour pressure is equal to the atmospheric pressure. Lowering pressure lowers the boiling point.

Question 10

Lattice

Answer 10

Repeating 3-D arrangement of atoms/ions/molecules in a crystal

Question 11

Kinetic theory of matter - changes of state

Answer 11

In solid, lattice structure. Once heated, particles have sufficient energy to break the lattice and become liquid. Heat is added and particles move faster, have enough energy to overcome attractive forces and escape as a vapour.

Question 12

Melting

Answer 12

Solid to liquid

Question 13

Freezing

Answer 13

Liquid to solid

Question 14

Vaporization

Answer 14

Liquid to gas

Question 15

Evaporation

Answer 15

Liquid to gas below boiling point - particles at the surface gain enough energy to escape as a vapour

Question 16

Boiling

Answer 16

Liquid to gas at boiling point, when external pressure is equal to vapour pressure (all particles gain enough energy to turn to vapour)

Question 17

Condensation

Answer 17

Gas to a liquid

Question 18

Sublimation

Answer 18

Solid to gas without passing through the liquid state

Question 19

Deposition

Answer 19

Gas to solid without passing through the liquid state

Question 20

Cooling curve - why is temperature constant for about 8 minutes?

Answer 20

Equilibrium is formed between heat given out due to formation of attractive forces and heat lost to environment exothermically.

Question 21

What is one mL and one L

Answer 21

mL = cm^3
L = dm^3

Question 22

Solute

Answer 22

Substance being dissolved

Question 23

Solvent

Answer 23

Liquid that dissolves the solute

Question 24

Solution

Answer 24

When a solute dissolves in a solvent

Question 25

Soluble

Answer 25

Substance that can dissolve in a solvent

Question 26

Insoluble

Answer 26

Substance that cannot dissolve in a solvent

Question 27

Miscible

Answer 27

Two liquids that can dissolve into each other

Question 28

Immiscible

Answer 28

Two liquids that cannot dissolve into each other

Question 29

Homogenous

Answer 29

All components in the same phase of matter

Question 30

Heterogenous

Answer 30

Components in different phases of matter

Question 31

Mixture

Answer 31

Combination of pure substances, has no definite or constant composition

Question 32

Filtration

Answer 32

Seperates solid particles from a liquid

Question 33

Solvation and evaporation

Answer 33

Mixture is warmed with a solvent, filtered to remove insoluble particles and evaporated

Question 34

Recrystillisation

Answer 34

Mixture is dissolved in solvent, heated, cooled and crystals are isolated by filtration (less soluble substance)

Question 35

Distillation

Answer 35

Used to seperate liquids from less volatile liquids or dissolves components based on boiling points

Question 36

Chromotography

Answer 36

Spot of mixture is placed on paper, and solvent rises up the paper

Question 37

Which atom doesn’t have a nucleus composed of neutrons and protons?

Answer 37

Hydrogen

Question 38

Which atom doesn’t have a nucleus composed of neutrons and protons?

Answer 38

Hydrogen

Question 39

What is relative atomic mass?

Answer 39

The weighted mean of the naturally occurring isotopes of the element relative to the C-12 atom

Question 40

What is the difference between relative atomic mass and atomic mass?

Answer 40

Atomic mass is the sum of protons and neutrons in the nucleus, and relative atomic mass is the weighted mean of natural isotopes of the element

Question 41

Nucleon

Answer 41

Protons and neutrons in the nucleus

Question 42

Radioisotope

Answer 42

The unstable form of an element that emits radiation to transform into a more stable form

Question 43

Relative abundance

Answer 43

Percentage of an isotope in a naturally occurring sample of the element

Question 44

Each element produces an emission spectrum - what is this?

Answer 44

Discrete lines at particular wavelengths corresponding to the differences between energy levels.

Question 45

Movement of electrons between shells is called what?

Answer 45

Electron transititions

Question 46

How can you tell the relative energy of a shell?

Answer 46

Energy emitted from electron transititions can be detected and wavelength measured

Question 47

What electron transitions produce UV light?

Answer 47

n=7/6/5/4/3/2/ to n=1

Question 48

Which electron transmitions produce infrared light

Answer 48

n=7/6/5/4 to n=3/4/5/6