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Northern IrelandCombined Science

C1 Structures, Trends, Reactions and Analysis

8 dot points across 8 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

What are acids and bases, how do they react, and how are salts made?

Acids, bases and alkalis in terms of hydrogen and hydroxide ions, the pH scale and indicators, neutralisation, the reactions of acids with metals, oxides, hydroxides and carbonates, and preparing soluble salts.
A focused CCEA GCSE Double Award Science (Chemistry Unit C1) answer on acids, bases and salts, covering the pH scale and indicators, neutralisation, the reactions of acids with metals, oxides, hydroxides and carbonates, and preparing soluble salts.
8 min answer →

What is an atom made of, and what are isotopes?

The structure of the atom in terms of protons, neutrons and electrons, their relative charges and masses, atomic number and mass number, isotopes, and calculating relative atomic mass from isotopic abundances.
A focused CCEA GCSE Double Award Science (Chemistry Unit C1) answer on atomic structure, covering protons, neutrons and electrons with their charges and masses, atomic number and mass number, isotopes, and calculating relative atomic mass from isotopic abundances.
8 min answer →

How do atoms bond, and how does bonding explain the properties of substances?

Ionic bonding as the transfer of electrons, covalent bonding as the sharing of electrons, metallic bonding as ions in a sea of delocalised electrons, drawing dot-and-cross diagrams, and how each type of structure explains properties.
A focused CCEA GCSE Double Award Science (Chemistry Unit C1) answer on chemical bonding, covering ionic bonding by electron transfer, covalent bonding by sharing, metallic bonding, dot-and-cross diagrams, and how each structure explains the properties of substances.
8 min answer →

What is the difference between elements, compounds and mixtures, and how do we separate them?

Elements, compounds and mixtures, the difference between physical and chemical change, and the separation techniques of filtration, crystallisation, simple and fractional distillation, and chromatography.
A focused CCEA GCSE Double Award Science (Chemistry Unit C1) answer on elements, compounds and mixtures, covering the difference between physical and chemical change, and the separation techniques of filtration, crystallisation, distillation and chromatography.
7 min answer →

What are the properties and trends of the alkali metals, the halogens and the noble gases?

The properties and reactivity trends of the Group 1 alkali metals, the Group 7 halogens including displacement reactions, and the Group 0 noble gases, and how these trends link to electron arrangement.
A focused CCEA GCSE Double Award Science (Chemistry Unit C1) answer on the groups of the Periodic Table, covering the Group 1 alkali metals, the Group 7 halogens and their displacement reactions, the Group 0 noble gases, and how the reactivity trends link to electron arrangement.
8 min answer →

How do we write balanced equations and use the mole to work out masses?

Writing chemical formulae, constructing word and balanced symbol equations with state symbols, relative formula mass, the mole, the relationship between moles, mass and relative formula mass, and using balanced equations to calculate reacting masses.
A focused CCEA GCSE Double Award Science (Chemistry Unit C1) answer on chemical equations and the mole, covering writing formulae and balanced symbol equations with state symbols, relative formula mass, the mole, and using equations to calculate reacting masses.
8 min answer →

How do we test for different ions and gases in the laboratory?

Flame tests and sodium hydroxide tests for metal ions, tests for halide, sulfate and carbonate ions, and the tests for hydrogen, oxygen, carbon dioxide and chlorine gases.
A focused CCEA GCSE Double Award Science (Chemistry Unit C1) answer on qualitative analysis, covering flame tests and sodium hydroxide tests for metal ions, tests for halide, sulfate and carbonate ions, and the tests for hydrogen, oxygen, carbon dioxide and chlorine.
7 min answer →

How is the Periodic Table organised, and how are electrons arranged in atoms?

Electron arrangement in shells for the first 20 elements, the link between outer electrons, group number and reactivity, and the modern organisation of the Periodic Table by atomic number into periods and groups with metals and non-metals.
A focused CCEA GCSE Double Award Science (Chemistry Unit C1) answer on the Periodic Table and electron arrangement, covering electron shells for the first 20 elements, the link between outer electrons, group number and reactivity, and the organisation of the table into periods and groups.
8 min answer →