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SingaporeCombined Science

Chemistry: Atoms, Bonding and the Mole

4 dot points across 4 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

What is an atom made of, and how does the periodic table organise the elements?

Describe the structure of the atom in terms of protons, neutrons and electrons, work out proton number and nucleon number, and explain how elements are arranged in the periodic table
A focused N(A)-Level answer on the atom. Protons, neutrons and electrons, proton and nucleon numbers, electron shells, and how groups and periods organise the periodic table.
8 min answer →

Why do atoms join together, and what is the difference between ionic and covalent bonding?

Explain why atoms form bonds, describe ionic bonding as the transfer of electrons and covalent bonding as the sharing of electrons, and relate bonding to simple properties
A focused N(A)-Level answer on bonding. Why atoms bond, ionic bonding by transferring electrons, covalent bonding by sharing, and how bonding links to melting point and conductivity.
8 min answer →

How does the arrangement of particles explain the three states of matter, and how do we separate mixtures?

Describe the three states of matter using the particle model, explain changes of state, and choose suitable methods to separate mixtures
A focused N(A)-Level answer on matter. The particle model of solids, liquids and gases, changes of state, and choosing filtration, evaporation, distillation or chromatography.
7 min answer →

How do chemists count atoms by weighing, and what does the mole let us calculate?

Define relative atomic mass and the mole, calculate relative formula mass, and find the number of moles from a given mass
A focused N(A)-Level answer on the mole. Relative atomic mass, relative formula mass, and using moles equals mass divided by relative formula mass in simple calculations.
8 min answer →