Answer : Normally in any chemical reaction, if the enthalpy change i.e. ΔH is positive which means it is greater than zero then it can be called as an Endothermic Reaction.
Whereas, the system under study is absorbing heat that is produced during the reaction. So if ΔH is found to be positive then it can be called as endothermic reaction.
Answer:
The reflection of sound waves
Explanation:
An echo is a reflection of sound that bounces of of one thing to another.
Answer:
They are similar in sense that both cannot dissolve any more solid unless heat or other factors are added. For eg if a solution is saturated it can no longer dissolve the given substance. But if the solution is heated, the solid will dissolved this is now said to be supersaturated.
Explanation:
The alignments of the planets would be the correct answer.<span />
The time taken by Carbon-14 to decay radioactively from 120g to 112.5g is 22,920 years.
<h3>How do we calculate the total time of decay?</h3>
Time required for the whole radioactive decay of any substance will be calculated by using the below link:
T = (n)(t), where
- t = half life time = 5730 years
- n = number of half life required for the decay
Initial mass of Carbon-14 = 120g
Final mass of Carbon-14 = 112.5g
Left mass = 120 - 112 = 7.5g
Number of required half life for this will be:
- 1: 120 → 60
- 2: 60 → 30
- 3: 30 → 15
- 4: 15 → 7.5
4 half lives are required, now on putting values we get
T = (4)(5730) = 22,920 years
Hence required time for the decay is 22,920 years.
To know more about radioactive decay, visit the below link:
brainly.com/question/24115447
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