A. Sedimentary rock. This is because sedimentary rock contains sediments and sometimes some fossils.
Answer:
(B) 73.0 hours.
Explanation:
- It is known that the decay of a radioactive isotope isotope obeys first order kinetics.
- Half-life time is the time needed for the reactants to be in its half concentration.
- If reactant has initial concentration [A₀], after half-life time its concentration will be ([A₀]/2).
- Also, it is clear that in first order decay the half-life time is independent of the initial concentration.
<em>So, the half-life of 201Tl when its concentration is 0.0136 M is (B) 73.0 hours.</em>
Think it though and always go back to the cause of the problem
2.3 M is the molarity of a solution that contains 2.3 moles of solute in 1.0 liter of solution.
Explanation:
Data given:
volume of the solution = 1 litre
number of moles of the solute = 2.3 moles
Molarity of a solution is given by number of moles of a given solute in a given volume in litres.
The unit of molarity = moles/litre
The formula used to calculate molarity is given by:
molarity =
Putting the values in the equation,
molarity =
molarity = 2.3
Thus the molarity of the given solution is 2.3 moles/litre.
The molarity of the solution is also written as 2.3 M.