Answer:
3NaOH+FeBr3>3NaBr+
Fe(OH)3
Explanation:
After writing the equation it has to be balanced
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
Answer:
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