GCSE Chemistry — Atoms and Isotopes

Led by John Dalton

The opening module of Edexcel GCSE Chemistry. Led by John Dalton, the Manchester schoolmaster who in 1808 gave chemistry its first quantitative atomic theory. The student traces the historical refinement of the atomic model through Thomson, Rutherford, and Bohr, masters the subatomic particles, and learns to work with isotopes and relative atomic mass.

1. Module 1

   Atoms and Isotopes

   Led by John Dalton

   The question

   What is an atom made of, how do we know, and why are most relative atomic masses on the periodic table not whole numbers? The spec asks the student to describe how Dalton's 1808 model has been refined by Thomson's, Rutherford's, and Bohr's experiments; recall the relative charges and masses of the three subatomic particles; account for atomic neutrality and the concentration of mass in the nucleus; apply atomic number and mass number; define isotopes; and calculate relative atomic masses from isotope abundance data.

   Outcome

   the student can describe Dalton's theory and its historical refinements, state the relative charges and masses of the proton, neutron, and electron, account for atomic neutrality and mass concentration, calculate p/n/e for any atom from its atomic number and mass number, define isotopes, and calculate relative atomic mass from isotope abundance data. *(Edexcel 1CH0 — Topic 1, spec points 1.1–1.12)*

   Sub-units

   1. ○ 1.1 Dalton's atomic theory and its historical refinement Open this unit → ✓ ↻
   2. ○ 1.2 The three subatomic particles: charge, mass, location Open this unit → ✓ ↻
   3. ○ 1.3 Atomic number, mass number, and particle counting Open this unit → ✓ ↻
   4. ○ 1.4 Isotopes and relative atomic mass Open this unit → ✓ ↻
   Begin the course → Print certificate of completion