Q5. A scientist is studying the reactions of the Group 1 and Group 2 elements. A First, the scientist compares how quickly the Group 1 elements react.
He adds some lithium to water. At the same time, he starts a stopwatch.
He measures the time taken for the bubbles to stop. He does the same for some other Group 1 elements.

I State one safety precaution the scientist should take, apart from wearing eye protection, when conducting the reactions of the group 1 metals.

(1 mark) ii Suggest two things the scientist could do to make the test fair. (1 mark) iii The scientist records their results in a table. In the table, the elements are listed in the same order as they are in the periodic table
. Element Time for bubbles to stop (s) lithium 122 sodium 80 potassium 61 Describe the pattern in the results, going down Group 1 from lithium to potassium.
(1 mark) b Next, the scientist adds some Group 2 elements to water. He writes his results in a table. In the table, the elements are listed in the same order as they are in the Periodic Table. Group 2 element Observations when added to cold water magnesium small bubbles form on surface of magnesium calcium bubbles vigorously strontium barium bubbles extremely vigorously i Predict what he will observe when he adds strontium to water. (1 mark) ii Give a reason for your prediction. (1 mark) Maximum 5 marks