It will take 28 days to let the radioactivity fall below 25%.
<h3>What is Half Life ?</h3>
Half life can be described as the time required by the radioactive compound to reduce to half of the original value of concentration.
It is given that
Radioactive phosphorus-32 decays with a half-life of 14.0 days
25% of the initial measure at what time =?
For 50% decay the time needed is 14 days
for decay of the next 50% of the amount left the time taken will be another 14 days
2nd half life = 25% decay of the substance = 28 days
Therefore it will take 28 days to let the radioactivity fall below 25%.
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The limiting reactant is the substance of the reactants that runs out first. The excess reactant is the substance with the greater amount than necessary to react completely with the limiting reactant after a chemical reaction.
Answer:
V₁ = 31.5 mL
Explanation:
Given data:
Initial molarity = 2.50 M
Initial volume required = ?
Final molarity = 0.150 M
Final volume = 525 mL
Solution:
Formula:
M₁V₁ = M₂V₂
M₁ = Initial molarity
V₁ = Initial volume
M₂ = Final molarity
V₂ = Final volume
Now we will put the values in formula.
2.50 M × V₁ = 0.150 M × 525 mL
V₁ = 0.150 M × 525 mL/ 2.50 M
V₁ = 78.75 M.mL/ 2.50 M
V₁ = 31.5 mL
Idk I think its a major addation Or Reading Or Socail Studies Sorry tho