GROWTH DEVELOPMENT CHILD
SUMMATIVE ASSESSMENT
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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They must be stored under oil, because they are unreactive metals.
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They must be stored under oil to keep air and water away from them.
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Because metals have less density
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None of the above
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Detailed explanation-1: -All the Group 1 elements are very reactive . They must be stored under oil to keep air and water away from them. When they react with water, Group 1 elements form metal hydroxides which are alkaline (with a pH above 7).
Detailed explanation-2: -Group 1 elements react with moist air. They are stored in oil to stop air and water vapour coming into contact with them. Moist air reacts with potassium to form potassium oxide. This creates a layer over the surface of the metal.
Detailed explanation-3: -Group 1 metals are very reactive and one way that indicates that they are so reactive is they are stored in liquid keresone or mineral oil to prevent or limit their reaction with oxygen.
Detailed explanation-4: -Sodium, potassium, and lithium are very reactive metals and react vigorously with air as well as water. Therefore, they are kept immersed in kerosene oil in order to prevent their contact with air and moisture.
Detailed explanation-5: -Alkali metals are extremely reactive with water producing flammable hydrogen gas that can ignite spontaneously.