Question 6
HThe diagram represents paths of positively charged alpha particles near a thin metal foil. The paths are schematic, not to scale.
a.[4]
Match the paths X, Y and Z to these observations: most particles pass straight through; some are deflected; a very small proportion turn back. Explain what the straight-through paths and the turn-back paths each show about atomic structure.
b.[2]
A student argues that the turn-back paths prove that electrons contain most of the mass of an atom. Explain why this conclusion is incorrect.
c.[2]
Two isotopes of the foil's element have the same atomic number but different mass numbers. Explain why these isotopes belong to the same element and why their atoms have different masses.
2.1 Atomic structure Questions
46 exam-style questions on Edexcel GCSE Chemistry 2.1 Atomic structure, covering 2.1.1 Development of the atomic model, 2.1.2 Structure of the atom and subatomic particles, 2.1.3 Mass number, isotopes and relative atomic mass, and 2.1.4 Calculating relative atomic mass from isotopic abundance. Each one has a worked solution and a mark scheme showing where the marks go.