The half-life of polonium-210, given that it decays from 98.3 micrograms to 12.3 micrograms in 414 days is 138 days
<h3>How to determine the number of half-lives </h3>
- Original amount (N₀) = 98.3 micrograms
- Amount remaining (N) = 12.3 micrograms
- Number of half-lives (n) =?
2ⁿ = N₀ / N
2ⁿ = 98.3 / 12.3
2ⁿ = 8
2ⁿ = 2³
n = 3
<h3>How to determine the half life </h3>
- Number of half-lives (n) = 3
- Time (t) = 414 days
- Half-life (t½) = ?
t½ = t / n
t½ = 414 / 3
t½ = 138 days
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Answer: A. Endothermic
Explanation:
In an endothermic reaction, heat is sucked in from the surrounding area by the reactants so that they may use it to react and form new products. This will therefore reduce the temperature in the said surrounding by the amount that the reaction needed.
This is what ice does when it melts. It sucks in the heat surrounding the area and then melts but leaves the area colder. For instance, putting ice in water ensures that the ice melts but because it sucked in the heat from the water to do so, the water gets colder as a result.
Answer:
as individual atoms
Explanation:
toms bond together to form compounds because in doing so they attain lower energies than they possess as individual atoms. A quantity of energy, equal to the difference between the energies of the bonded atoms and the energies of the separated atoms, is released, usually as heat.