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

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."

the answer is d. 74.02