Which of these elements reacts rapidly when dropped in water? a. rubidium (rb) b. magnesium (mg) c. cobalt (co) d. argon (ar) e. cadmium (cd)

Answer : The correct option is, (a) rubidium (Rb)

Explanation :

The general trend of the reactivity of the metal is,

The reactivity of the metals increases as we go down in the periodic table and the reactivity of the metals decreases as we go from left to right in the periodic table.

Therefore, the reactivity of metal in decreasing order will be,

Rb > Mg > Co > Cd > Ar

As per question, when the given elements dropped in water then the rubidium (Rb) is element which is most reactive that reacts rapidly with the water.

Hence, the element reacts rapidly with water is, rubidium (Rb).

explanation:

two years ago, when picking flowers in the mountains back of yosemite valley, i found a book. it was blotted and storm-beaten; all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however; many of the inner pages were well preserved. and although all were more or less stained and torn, whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today; its granite pages have been torn and blurred by the same storms that wasted the castaway book.

two years ago, when picking flowers in the mountains back of yosemite valley; i found a book. it was blotted and storm-beaten, all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however, many of the inner pages were well preserved. and although all were more or less stained and torn; whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today, its granite pages have been torn and blurred by the same storms that wasted the castaway book.