Answer: (E) 300 bq
Explanation:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha, beta particles or gamma-radiations. The radioactive decay follows first order kinetics.
Half life is represented by 
Half life of Thallium-208 = 3.053 min
Thus after 9 minutes , three half lives will be passed, after ist half life, the activity would be reduced to half of original i.e. 
, after second half life, the activity would be reduced to half of 1200 i.e. 
, and after third half life, the activity would be reduced to half of 600 i.e. 
,
Thus the activity 9 minutes later is 300 bq.
Answer:
0.86L.
Explanation:
1mol of Zn has mass of 65.39g . The amount of Zn is 2.5g65.39g/mol=0.038mol
Answer:
B. as a food preservative in the manufacture of detergents
.........
Nitrogen is more reactive than oxygen and oxygen than chlorine
Based on Le Chatelier's principle, if the equilibrium of a system is disturbed by changing the temperature, pressure or concentration, then it will shift in a direction to undo the effect of the induced change.
The given equilibrium is:
A + B ↔ AB
Removal of the reactant A implies that the concentration of A has decreased, therefore the equilibrium will shift in a direction to produce more of A. Thus, it will shift to the left and the rate of the reverse or backward reaction will increase.
