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Northern IrelandChemistry

Unit 1 Structures, Trends, Chemical Reactions and Analysis

5 dot points across 5 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How do non-metals bond by sharing electrons?

Covalent bonding as the sharing of electron pairs between non-metal atoms, drawing dot-and-cross diagrams for simple molecules, and the properties of simple molecular substances.
A CCEA GCSE Chemistry answer on covalent bonding, covering how non-metal atoms share pairs of electrons to fill their outer shells, dot-and-cross diagrams for molecules such as hydrogen, water, ammonia and methane, and why simple molecular substances have low melting points and do not conduct.
8 min answer →

Why do diamond, graphite and silicon dioxide behave so differently?

Giant covalent structures, the structures and properties of diamond, graphite and silicon dioxide, and how bonding explains hardness, melting point and electrical conductivity.
A CCEA GCSE Chemistry answer on giant covalent structures, covering the structures of diamond, graphite and silicon dioxide, and how their covalent bonding explains very high melting points, hardness, and why graphite conducts electricity while diamond does not.
8 min answer →

How do metals and non-metals bond by transferring electrons?

Ionic bonding as the transfer of electrons to form charged ions, drawing dot-and-cross diagrams, the giant ionic lattice, and how the structure explains the properties of ionic compounds.
A CCEA GCSE Chemistry answer on ionic bonding, covering how electrons transfer from metals to non-metals to form ions, dot-and-cross diagrams, the giant ionic lattice, and how this structure explains the high melting points, conductivity and solubility of ionic compounds.
9 min answer →

How are metals bonded, and why are alloys harder than pure metals?

Metallic bonding as positive ions in a sea of delocalised electrons, how this explains the properties of metals, and why alloys are harder than the pure metal.
A CCEA GCSE Chemistry answer on metallic bonding, covering the model of positive ions in a sea of delocalised electrons, how it explains conductivity, malleability and high melting points, and why alloys are harder than the pure metal.
8 min answer →

What are nanoparticles, and why do they behave differently from bulk material?

Nanoparticles and nanoscience, the large surface area to volume ratio of nanoparticles, their uses, and the benefits and risks of nanotechnology.
A CCEA GCSE Chemistry answer on nanoparticles, covering their size, the large surface area to volume ratio that makes them so reactive and useful, their applications in sunscreens, catalysts and medicine, and the benefits and possible risks of nanotechnology.
8 min answer →