Pearson Edexcel International GCSE Chemistry — Unit 1 Revision Checklist

Vocabulary practice flashcards based on the Pearson Edexcel International GCSE Chemistry Unit 1 revision checklist covering principles of chemistry, inorganic chemistry, physical chemistry, and chemical calculations.

Atomic number

The number used to determine the identity and number of protons in atoms and ions.

Mass number

The value used alongside atomic number to determine the numbers of protons, neutrons, and electrons in atoms and ions.

Isotopes

Different forms of an element whose percentage abundances are used to calculate relative atomic mass.

Relative atomic mass

The average mass value of an element calculated using isotope abundances.

Group number

A number in the Periodic Table that relates to the number of outer-shell electrons for main-group elements.

Noble gases

Elements in the Periodic Table characterized by being unreactive.

Halogen displacement reactions

Reactions involving Group 7 elements that can be predicted and explained based on periodic trends.

Ionic bonding

A type of chemical bonding between positive and negative ions that can be represented using dot-and-cross diagrams.

Covalent bonding

A type of chemical bonding illustrated using dot-and-cross diagrams and present in simple molecular and giant structures.

Diffusion

A physical process explained through the arrangement and movement of particles in solids, liquids, and gases.

Fractional distillation

A physical separation technique used to separate mixtures, distinct from simple distillation.

$R_f$ value

A chromatographic value calculated using: $\text{distance travelled by substance} \div \text{distance travelled by solvent}$.

Law of conservation of mass

A fundamental principle applied to chemical calculations and when writing balanced symbol equations.

Relative formula mass ($M_r$)

A calculated chemical value used to determine moles via $\text{moles} = \text{mass} \div M_r$.

Empirical formula

The simplest formula of a compound determined from its elemental composition or experimental data.