paper 1

Question 1

What are the relative charges of protons, neutrons, and electrons?

Answer 1

Proton: +1, Neutron: 0, Electron: –1

Question 2

What is the mass number?

Answer 2

Number of protons + neutrons

Question 3

What is the atomic number?

Answer 3

Number of protons (and electrons in a neutral atom)

Question 4

What is an isotope?

Answer 4

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

Question 5

Why do isotopes have the same chemical properties?

Answer 5

Same number of electrons

Question 6

How are elements arranged in the modern periodic table?

Answer 6

By increasing atomic number

Question 7

What are the Group 1 elements called?

Answer 7

Alkali metals

Question 8

How do alkali metals react with water?

Answer 8

Vigorously - produce hydrogen gas and metal hydroxide

Question 9

What are the Group 7 elements called?

Answer 9

Halogens

Question 10

What happens to reactivity in Group 7 going down the group?

Answer 10

Reactivity decreases

Question 11

What type of bonding occurs between metals and non-metals?

Answer 11

Ionic bonding

Question 12

What happens in ionic bonding?

Answer 12

Electrons are transferred from metal to non-metal

Question 13

What is covalent bonding?

Answer 13

Sharing of electron pairs between non-metals

Question 14

What are the properties of giant ionic compounds?

Answer 14

High melting/boiling points, conduct electricity when molten or dissolved

Question 15

Why do simple covalent molecules have low melting points?

Answer 15

Weak intermolecular forces

Question 16

Why does diamond have a high melting point?

Answer 16

Giant covalent structure, strong covalent bonds throughout

Question 17

What is the structure of graphite?

Answer 17

Layers of carbon atoms, delocalised electrons, soft and slippery

Question 18

Why can graphite conduct electricity?

Answer 18

Delocalised electrons can move

Question 19

What is a fullerene?

Answer 19

A molecule of carbon shaped into hollow tubes, spheres, or cages

Question 20

What is a nanoparticle?

Answer 20

1–100 nanometres in size; large surface area to volume ratio

Question 21

What is the formula for % atom economy?

Answer 21

(Mass of desired product / total mass of all products) × 100

Question 22

What is the formula for concentration?

Answer 22

Concentration = mass / volume

Question 23

What is the formula for number of moles?

Answer 23

Moles = mass / Mr

Question 24

What is the relative formula mass (Mr)?

Answer 24

Sum of the atomic masses in a compound

Question 25

What is a limiting reactant?

Answer 25

The reactant that's completely used up first and limits product formed

Question 26

What is the reactivity series (top 5)?

Answer 26

Potassium, Sodium, Calcium, Magnesium, Aluminium

Question 27

What is the general word equation for metal + acid?

Answer 27

Metal + acid → salt + hydrogen

Question 28

What is a redox reaction?

Answer 28

One substance is oxidised, the other is reduced

Question 29

How do you test for hydrogen gas?

Answer 29

Lit splint → squeaky pop

Question 30

What is a base?

Answer 30

Substance that reacts with an acid to form a salt and water

Question 31

What is electrolysis?

Answer 31

Using electricity to split an ionic compound into its elements

Question 32

What is the half-equation at the cathode for lead bromide?

Answer 32

Pb²⁺ + 2e⁻ → Pb

Question 33

What happens at the anode?

Answer 33

Negative ions (anions) lose electrons (oxidation)

Question 34

What products form when electrolysing brine (NaCl solution)?

Answer 34

Hydrogen (cathode), chlorine (anode), sodium hydroxide (in solution)

Question 35

Why is cryolite used in aluminium extraction?

Answer 35

Lowers the melting point of aluminium oxide, saving energy

Question 36

What is an exothermic reaction?

Answer 36

A reaction that releases energy to the surroundings (e.g. combustion)

Question 37

What is an endothermic reaction?

Answer 37

A reaction that absorbs energy from the surroundings (e.g. thermal decomposition)

Question 38

What is activation energy?

Answer 38

Minimum energy required to start a reaction

Question 39

How do you test for an exothermic reaction in a lab?

Answer 39

Measure temperature rise in a solution

Question 40

Name a use of an endothermic reaction.

Answer 40

Sports injury ice packs