PAPER 1 GCSE

Question 1

What is an ELEMENT?

Answer 1

A substance containing only one type of atom
eg. Mg, O2

Question 2

What is a COMPOUND?

Answer 2

A substance containing two or more different types of atoms which are CHEMICALLY BONDED
eg. H20

Question 3

Why must equations be balanced?

Answer 3

Atoms cannot be created or destroyed due to CONSERVATION OF MASS

Question 4

What is a PRO TIP when balancing equations?

Answer 4

Start with atoms in a compound; end with elements.

Question 5

What is a MIXTURE?

Answer 5

A mixture consists of different substances NOT CHEMICALLY BONDED
eg. air, solutions.

Question 6

What does FILTRATION do?

Answer 6

Removes large, insoluble particles from a liquid
eg. sand from water

Question 7

What does CRYSTALLISATION do?

Answer 7

Leaves behind crystals of a dissolved substance (solute)

Question 8

What does SIMPLE DISTILLATION do?

Answer 8

Involves condensing the evaporated solvent and collecting it

Question 9

What does FRACTIONAL DISTILLATION do?

Answer 9

Can separate liquids due to their different boiling points

Question 10

What does CHROMATOGRAPHY do?

Answer 10

Separates mixtures of soluble substances in a solution

Question 11

What are the 3 main states of matter?

Answer 11

Solid
Liquid
Gas

Question 12

What is MELTING?

Answer 12

Solid -> Liquid

Question 13

What is SOLIDIFICATION/ FREEZING?

Answer 13

Liquid -> Solid

Question 14

What is EVAPORATION/ BOILING?

Answer 14

Liquid -> Gas

Question 15

What is CONDENSATION?

Answer 15

Gas -> Liquid

Question 16

What is SUBLIMATION?

Answer 16

Solid -> Gas

Question 17

Particles in a SOLID:

Answer 17

• Regular arrangement (lattice) and vibrate about fixed positions.
• Cannot be compressed

Question 18

Particles in a LIQUID:

Answer 18

• Irregular arrangement and are able to move past each other
• Cannot be compressed

Question 19

Particles in a GAS:

Answer 19

• Far apart, move randomly at fast speeds (high energy)
• Can be compressed

Question 20

Are new substances made after a physical change?

Answer 20

No

Question 21

What is needed to overcome the electrostatic forces of attraction between particles to melt/ evaporate?

Answer 21

Energy (heat)

Question 22

What are the state symbols?

Answer 22

(s) = SOLID
(l) = LIQUID
(g) = GAS
(aq) = AQUEOUS (dissolved or in a solution)

Question 23

Atomic Structure HISTORY (briefly):

Answer 23

ANCIENT GREEKS: thought matter to be made of invisible particles

JJ THOMPSON: Created the ‘plum pudding’ model

ERNEST RUTHERFORD: Discovered that the nucleus was small and positively charged by finding that most alpha particles went straight through a gold ‘leaf’; very few deflected back.. Atoms mostly empty space

NEILS BOHR: Deduced that electrons exist in ‘shells’. JAMES CHADWICK determined that the nucleus must contain NEUTRONS as well as protons.

Question 24

What are the RELATIVE CHARGES of the three subatomic particles?

Answer 24

Proton = +1
Neutron = 0
Electron = -1

Question 25

What are the RELATIVE MASSES of the three subatomic particles?

Answer 25

Proton = 1 Neutron = 1 Electron = 0.0005

Question 26

What is the ATOMIC NUMBER?

Answer 26

The number of protons/ electrons in a nucleus

Question 27

What is an ISOTOPE?

Answer 27

Atoms with the same number of protons but a different number of neutrons.

Question 28

What happens if an atom has a different number of protons and electrons?

Answer 28

It is an ION.

Question 29

What is the MASS NUMBER also known as?

Answer 29

RELATIVE ATOMIC MASS/RAM/Ar

Question 30

What is the MASS NUMBER?

Answer 30

The number of PROTONS and NEUTRONS in a nucleus.

Question 31

Why might some MASS NUMBERS on your periodic table be decimals?

Answer 31

They are the AVERAGE mass of all isotopes

Question 32

How do you work out the AVERAGE MASS?

Answer 32

Average mass = total mass of 100 atoms/ 100

Question 33

The RELATIVE ABUNDANCE of Chlorine-35 is 75% Chlorine-37 is 25% How would this look in the formula for average mass?

Answer 33

(35x75)+(37x25)/ 100 = 35.5

Question 34

How were the elements initially ordered in the periodic table?

Answer 34

According to their atomic 'weight'

Question 35

How did Dmitri Mendeleev organise the periodic table?

Answer 35

He grouped elements together based on their properties.

Question 36

Why did Dmitri Mendeleev believe there were gaps in his table?

Answer 36

Elements had yet to be discovered. In time, this was proven to be largely correct, and is the basis of the modern periodic table.

Question 37

Electron configuration?

Answer 37

2,8,8,2

Question 38

Which ions do metals form?

Answer 38

Positive

Question 39

Which ions do non-metals form?

Answer 39

Negative

Question 40

What is Group 1 called?

Answer 40

The Alkali Metals

Question 41

What is Group 7 called?

Answer 41

The Halogens

Question 42

What is Group 0/8 called?

Answer 42

The Noble Gases

Question 43

How does the reactivity of Group 1 change throughout the group? Why?

Answer 43

Group 1 gets more reactive as you go down the group. This is because the outer electron is further from the nucleus so the attraction between the outer electrons and the nucleus decreases.

Question 44

How does the reactivity of Group 7 change throughout the group? Why?

Answer 44

They get less reactive as you go down the group. This is because the number of electron shells increases, so the attraction between the nucleus and outer electrons decrease which makes it harder to gain an electron.

Question 45

How does the reactivity of Group 0/8 change throughout the group? Why?

Answer 45

The are unreactive as they already have an empty outer shell.