An element is a solid at room temperature but soft enough to be cut with an ordinary knife. when placed in water, the element reacts violently. what element is it? an element is a solid at room temperature but soft enough to be cut with an ordinary knife. when placed in water, the element reacts violently. what element is it?

There are actually a lot of possible answers for this. Most elements are solid in room temperature especially metals. In particular, the elements in group 1 are solid in room temperature but have a soft texture. They also react violently in water, especially cold. I found the same problem from another website which have choices. Since Sodium (Na) is a Group 1 element, this must be the answer.

Ocean-Continent Convergent Plate Boundaries