GCSE Chemistry: Atomic Structure & Periodic Table — Revision Workbook

Inside GCSE Chemistry: Atomic Structure & Periodic Table — Revision Workbook

sort elements, compounds and mixtures and label the atom, count protons, neutrons and electrons and work out atomic and mass numbers, identify isotopes and calculate a relative atomic mass, read electronic structures and track the atomic model from Dalton to Bohr, then read the periodic table by groups and periods and predict Group 1, Group 7 and Group 0 trends. About 30 minutes.

Learning objectives

• atoms, elements, compounds and mixtures — telling a single type of atom from chemically joined elements and from physical mixtures such as air;
• atomic structure — the nucleus, protons (+1), neutrons (0) and electrons (-1), and their relative charges and positions;
• atomic number, mass number and isotopes — counting protons, neutrons and electrons, and calculating relative atomic mass from isotope abundances;
• electronic structure (2, 8, 8) and the development of the atomic model from Dalton to Thomson, Rutherford and Bohr;
• the periodic table — groups and periods, Mendeleev, metals and non-metals, and the trends in Group 1 (alkali metals), Group 7 (halogens, including displacement), Group 0 (noble gases) and the transition metals.

Activities in this book

1. Task 1 — Atoms, Elements, Compounds & Mixtures

   an element contains only one type of atom; a compound is two or more elements chemically joined; a mixture is substances that are not chemically joined and can be separated physically. Every atom has a tiny central nucleus of protons (charge +1) and neutrons (charge 0), with electrons (charge -1) in shells around it.

2. Task 2 — Atomic Number, Mass Number & Isotopes

   the atomic number is the number of protons; the mass number is protons + neutrons. A neutral atom has equal protons and electrons, so number of neutrons = mass number - atomic number. Isotopes are atoms of the same element with the same protons but different neutrons. Relative atomic mass is the average mass of the isotopes, weighted by their abundance.

3. Task 3 — Electronic Structure & the Atomic Model

   electrons fill shells from the inside out: 2 in the first shell, then 8, then 8. The model changed over time: Dalton (tiny solid spheres), Thomson (plum pudding — electrons in a ball of positive charge), Rutherford (a small positive nucleus, from alpha-particle scattering) and Bohr (electrons in fixed shells at set energy levels).

4. Task 4 — The Periodic Table & Group Trends

   columns are groups, rows are periods; metals are on the left, non-metals on the right. Group 1 = alkali metals, Group 7 = halogens, Group 0 = noble gases. Down Group 1 reactivity increases; down Group 7 reactivity decreases, and a more reactive halogen displaces a less reactive one. Transition metals (in the middle) are less reactive than Group 1 and form coloured compounds.

5. Task 5 — Explain the Atomic Model (6 marks)

   this is an exam-style writing task, so it is not auto-marked. Aim for six clear points, using the correct keywords (nucleus, electrons, shells, alpha particles) and putting the scientists in the right order.

Suggestions for teaching

• Fix the vocabulary first. Secure element, compound and mixture before moving inside the atom to the three sub-atomic particles and their charges.
• Count before you calculate. Rehearse atomic number = protons, mass number = protons + neutrons, and neutrons = mass number - atomic number, then build up to relative atomic mass.
• Weighted averages. Model the RAM calculation step by step: multiply each isotope mass by its percentage, add, then divide by 100.
• Order the models. Rehearse Dalton → Thomson → Rutherford → Bohr, and link the nuclear model to the alpha-particle scattering evidence.
• Read the table by position. Link group number to family and drill the trends: reactivity increases down Group 1 but decreases down Group 7, with displacement following the halogen order.