An element that is likely to combine with other elements to form new substances is said to be . A. buoyant
B. chemically reactive
C. metallic
D. solid at room temperature

B. Chemically reactive

Explanation:

A Chemically reactive element is an element that is likely to combine with another element to form new substances

The reactivity of the element depends on the number of electrons in the outermost energy level and even the distance of the outermost energy level from the nucleus.  From the periodic table, Fluorine is the most reactive non-metal while francium is the most chemically reactive metal