question_answer 56)

    An element A is soft and can be cut with a knife. This is very reactive to air and cannot be kept open in air. It reacts vigorously with water. Identify the element from the following. (a) Mg                                   (b) Na                                   (c) P                                       (d) Ca

Answer:

                  (b) From the properties of the element described in the question, it can be said surely that the element is sodium (Na).