Answer: The definition of an endothermic reaction is that the products have higher energy than the reactants, resulting in a positive enthalpy of reaction.
Explanation:
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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Answer:
0.0342 moles
Explanation:
Moles and Mass are related as,
Moles = Mass / M.Mass
M.Mass of NaCl = 58.44 g/mol
Putting values,
Moles = 2.00 g / 58.44 g/mol
Moles = 0.0342 moles
The answer is Sodium Sulfite
Hope it helps