Student B because it requires a hypothesis
Explanation:We have momemtum = mass X velocity
p = mv
OR, p/m = v
v = (125kg m/s)25kg
v = 125/25 m/s
v = 5 m/s
<span>Of the answers listed option B looks like the most complete. Ie "Check for the presence of alpha, beta, and gamma particles." the significant presence of these particles is a specific indicator of radioactive decay, i.e: unstable atoms spontaneously undergoing a nuclear reaction.</span>
The liquid nitrogen freezes the balloon and shatters it on contact