S1

Question 1

elements

Answer 1

primary constituents of matter, which cannot be chemically broken down into simpler substances

Question 2

compounds

Answer 2

consist of atoms of different elements chemically bonded together in a fixed ratio

Question 3

mixtures

Answer 3

contain more than one element or compound in no fixed ratio, which are not chemically bonded and so can
be separated by physical methods

Question 4

kinetic molecular theory

Answer 4

a model to explain physical properties of matter (solids, liquids and gases) and
changes of state

Question 5

temperature

Answer 5

measure of average kinetic energy of particles

Question 6

What are the properties of solids?

Answer 6

fixed shape
fixed volume
cannot be compressed

Question 7

What are the properties of liquids?

Answer 7

no fixed shape, take shape of their container
fixed volume
can flow
cannot be compressed

Question 8

What are the properties of gases?

Answer 8

no fixed shape, take shape of their container
no fixed volume, take up volume of their container
can flow
can be compressed

Question 9

Mixtures can be further categorised as being either

Answer 9

homogeneous or heterogeneous

Question 10

heterogeneous

Answer 10

has visible phases or boundaries such as those that can be seen between the oil and the water. The composition of a heterogeneous mixture is non-uniform, meaning that different parts of the mixture have a different composition

Question 11

Homogeneous

Answer 11

do not have visible phases or boundaries. They have a uniform composition meaning that the components of the mixture are equally distributed and in the same state, making the composition the same throughout the mixture. An example of a homogeneous mixture is the air that we breathe.

Question 12

convert between values in the Celsius and Kelvin scales

Answer 12

K = C + 273

Question 13

isotopes

Answer 13

atoms of the same element with different numbers of neutrons

Question 14

emission spectra are produced by

Answer 14

atoms emitting photons when electrons in excited states return to lower energy
levels

Question 15

the line emission spectrum of hydrogen provides evidence for

Answer 15

the existence of electrons in discrete energy levels,
which converge at higher energies

Question 16

the main energy level is given an integer number, n, and can hold a maximum of

Answer 16

2n2 electrons

Question 17

a more detailed model of the atom describes the division of the main energy levels into

Answer 17

s, p, d and f sublevels of
successively higher energy

Question 18

continuous spectrum shows

Answer 18

all the wavelengths or frequencies of visible light from red to violet.

Question 19

emission line spectrum only shows

Answer 19

specific wavelengths or frequencies of light. These are shown as coloured lines on a black background that converge at high energy

Question 20

formation of an emission line spectrum

Answer 20

Electrons emit energy as they transition from higher to lower energy levels.

Question 21

mole (mol)

Answer 21

SI unit of amount of substance

Question 22

one mole contains

Answer 22

exactly the number of elementary entities given by the Avogadro constant

Question 23

masses of atoms are compared on a scale relative to

Answer 23

12 C and are expressed as relative atomic mass (Ar) and relative
formula mass (Mr)

Question 24

empirical formula of a compound gives

Answer 24

simplest ratio of atoms of each element present in that compound

Question 25

the molecular formula gives the

Answer 25

actual number of atoms of each element present in a molecule

Question 26

molar concentration is determined by

Answer 26

amount of solute and the volume of solution

Question 27

Avogadro’s law states that

Answer 27

equal volumes of all gases measured under the same conditions of temperature and
pressure contain equal numbers of molecules

Question 28

Avogadro’s law applies to

Answer 28

ideal gases.

Question 29

an ideal gas consists of

Answer 29

moving particles with negligible volume and no intermolecular forces; all collisions between
particles are considered elastic

Question 30

real gases deviate from

Answer 30

the ideal gas model, particularly at low temperature and high pressure

Question 31

the molar volume of an ideal gas is

Answer 31

constant at a specific temperature and pressure