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.
Learn this properly: Atoms, Elements and CompoundsThe alkali metals are found in Group 1 of the periodic table. The transition metals are found in the central block of the periodic table.
A student compared a sample of potassium (a Group 1 metal) with a sample of iron (a transition metal).
Compare the alkali metals with the transition metals. In your answer you should describe and explain differences in their physical properties, reactivity and the types of compound they form. (6 marks)
Chlorine exists as two main isotopes. Information about a sample of chlorine is shown in the table.
| Isotope | Mass number | Relative abundance / % |
|---|---|---|
| Chlorine-35 | 35 | 75 |
| Chlorine-37 | 37 | 25 |
(a) State what is meant by the term isotopes. (2 marks)
(b) Calculate the relative atomic mass of this sample of chlorine. Give your answer to 1 decimal place. (2 marks)
An atom of sodium can be represented as 1123Na.
(a) State the number of protons, neutrons and electrons in this atom. (2 marks)
(b) Write the electronic structure of this sodium atom (for example, in the form 2,8,1). (1 mark)
A mixture contains two coloured dyes, X and Y, dissolved in water, together with insoluble sand.
A student wants to obtain a pure, dry sample of solid sand, and then separate the two dyes from the remaining liquid.
(a) Name the separation technique the student should use to remove the insoluble sand from the liquid. (1 mark)
(b) The student then has a solution of dye X in water. Name the technique that should be used to obtain pure water from this solution, and explain how it works. (2 marks)
Iron is a transition metal. It is used as a catalyst in the Haber process, and it forms compounds such as iron(II) chloride and iron(III) chloride.
Explain what these two pieces of information tell you about two properties of transition metals that are not shown by Group 1 metals. (2 marks)
In the early 1800s, elements were arranged in order of their atomic weight. Later, Dmitri Mendeleev produced a periodic table that is closer to the modern one.
State the property used to arrange the elements in the modern periodic table. (1 mark)