Half life is the time taken by a radioactive isotope to decay by half its original mass.
The original mass is 200 g
Time taken is 60 hours
Final mass is 25 g
Therefore;
Final mass = Original mass × (1/2)^n; where n is the number of half lives.
25 = 200 (1/2)^n
1/8 = (1/2)^n
n = 3
Three half lives = 60 hours
1 half lives = 20 hours
Therefore; the half life of the radioactive nucleus is 20 hours
D) The objects particles move closer together.
Elements/molecules will absorb a photon if energy, which will put them into an excited state. They will then emit that same energy back in order to come back down to their ground state energy.
The mass percent of sugar in the solution is 1.225%
<u><em>calculation</em></u>
mass percent = [(mass of solute /mass of solution ) x 100]
mass of solute ( mass of a substance that dissolve in another substance)
= 2.45 g
mass of solution( mass of a substance that dissolves a solute) =200.0 g
Therefore mass percent = 2.45 g/200.0 g x 100 = 1.225% of sugar in solution
