6 exam-style questions with full mark schemes and model answers. Write your own answer and the AI examiner marks it against the mark scheme.
The idea we use for the structure of the atom has changed many times as scientists carried out new experiments and gathered new evidence.
Describe how the model of the atom developed from the earliest idea of tiny solid spheres through to the nuclear model used today. In your answer you should refer to the plum pudding model, the alpha-particle scattering experiment, and the later work that led to the ideas of electron shells (energy levels) and the neutron.
(6 marks)
Copper exists as a mixture of two isotopes. Data for a sample of copper are shown in the table.
| Isotope | Mass number | Abundance in the sample / % |
|---|---|---|
| copper-63 | 63 | 70 |
| copper-65 | 65 | 30 |
(a) Explain what is meant by the term isotopes. (2 marks)
(b) Calculate the relative atomic mass of copper in this sample. Give your answer to one decimal place and show your working. (2 marks)
An atom of sodium can be represented by the symbol below.
1123Na
(a) State the number of protons, neutrons and electrons in this atom. (2 marks)
(b) Give the electronic structure of this sodium atom. (1 mark)
The particle model can be used to explain the three states of matter and the changes between them.
(a) Describe the arrangement and movement of the particles in a liquid. (2 marks)
(b) Name the change of state that happens when a gas turns directly into a solid. (1 mark)
A student heats a pure solid until it melts and then boils. They record a heating curve of temperature against time.
Explain why the temperature stays constant during melting, even though the substance is still being heated. (2 marks)
Two atoms are isotopes of the same element.
State the one type of subatomic particle whose number is different between the two isotopes. (1 mark)