Answer:
Alpha particles, Beta particles, Gamma rays
Alpha Is the least harmful
Beta is second most harmful
Gamma is most dangerous
Explanation:
Gaining of electrons is reduction and loss of electrons is oxidation.
<em>Hope this helped! :)</em>
Amount of Niobium-91 initially
= 300/91 =3.2967mol
2040 years = 3 ×680 = 3 half-lives
therefore, amount left = 0.4121mol
mass of Niobium-91 remaining = 0.4121 ×91 =37.5g
