Answer: 6.98
The Relative Atomic Mass of Li = (98*7 + 2*6)/98+2
RAM of Li = (686+12)/100
RAM of Li= 6.98
Answer is 0.7 g
Reason: Given: mass of Fe = 5.60 gWe know that, half life of Fe-53 = t1/2 (Fe-53) = 8.51 min.
Thus, after 25.53 mins, number of half life passed = 25.53/8.51= 3
Now, Amount left after first half life = 5.60g/2 = 2.80 g
Amount left after second half life = 2.80g/2 = 1.40 g
Amount left after third half-life = 1.40g/2 = 0.7g.
True is the correct answer
12. Substances
13. Isotopes
14. Atomic
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