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6. Some of the elements in the periodic table are metals - Edexcel - GCSE Chemistry - Question 6 - 2019 - Paper 1
Question 6
6. Some of the elements in the periodic table are metals. (a) The electronic configuration of a metal is 2.8.3 Which row shows the group and period of the periodic ... show full transcript
Worked Solution & Example Answer:6. Some of the elements in the periodic table are metals - Edexcel - GCSE Chemistry - Question 6 - 2019 - Paper 1
Step 1
Which row shows the group and period of the periodic table where this metal is found?
Answer
The electronic configuration 2.8.3 indicates that the metal is in Group 3 and Period 3 of the periodic table. This is because the outer shell has three electrons, placing it in Group 3, and the first two shells are filled, indicating it is in Period 3.
Step 2
Describe what you would see when a small piece of rubidium is dropped on to water.
Answer
When rubidium is dropped into water, it reacts vigorously, producing hydrogen gas and forming rubidium hydroxide. This reaction is highly exothermic, causing the rubidium to fizz and may even ignite the hydrogen gas. The metal will move around on the surface of the water as it reacts.
Step 3
Explain, in terms of their electronic configurations, why lithium is less reactive than potassium.
Answer
Lithium's electron configuration is 2.1, indicating it has one outer electron, while potassium's configuration is 2.8.8.1, with one outer electron as well. However, potassium has more electron shells (four shells) compared to lithium's two. This leads to increased distance of the outer electron from the nucleus in potassium and greater shielding from the inner-shell electrons. Therefore, the outer electron in potassium can be lost more easily, making it more reactive compared to lithium.