Mass, if you know what element you are working with.
Answer:
B. Cl.
Explanation:
These are Group 7 elements whose reactivity reduces as you go down the group. Chlorine has a smaller atoms than the rest and has a stronger tendency to grab an electron in its valency shell. This is because its nucleus is closer to the outer electrons than the other elements.
Answer:
the answer to this question is option A mark me as brainliest
mark me as brainliest