Summary Chemistry A levels Definitions and Key Points

Modules 2: Foundation in chemistry
Atom and RAM

State what is meant by isotopes (1)

• Atoms of the same element with the same numbers of protons AND

• With different numbers of neutrons and different masses



Define the term relative isotopic mass (2)


• The mass of an isotope

• Compared with 1/12th the mass of a carbon-12 atom whose mass is
exactly 12




Define the term relative atomic mass (3)

• The weighted mean mass of an atom of an element

• Compared with 1/12th the mass of a carbon-12 atom

• Whose mass is exactly 12

,Acid and redox



Define a salt (1)

• The H+ ion in an acid has been replaced by a metal ion/ NH4+ ion



Why is ammonia acting as a base in this neutralisation? (1)

• Accepts H+



Define an acid (1)

• A proton donor



What is meant by a mole? (1)

• A mole is the number of atoms present in exactly 12g of carbon-12
isotope

, Amount of substances



PV = nRT where
P is in Pa

V is in m3

N is the number of mole

R is a constant

T is in K



• Water of crystallisation is the water associated with a salt that is
essential for it to form a crystalline structure


• Blue crystals of hydrated copper (II) sulfate


• White anhydrous copper (II) sulfate



How to make sure the experiment is accurate?

• Heat to constant mass

• No further decomposition