Answer:
A = 349 g.
Explanation:
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In this case, since the radioactive decay kinetic model is based on the first-order kinetics whose integrated rate law is:

We can firstly calculate the rate constant given the half-life as shown below:

Therefore, we can next plug in the rate constant, elapsed time and initial mass of the radioactive to obtain:

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Answer:
renewable energy sources such as solar and wind DONT emit carbon dioxide and other greenhouse gases that contribute to global warming
Explanation:
Answer:Chemical reactions often involve changes in energy due to the breaking and formation of bonds. Reactions in which energy is released are exothermic reactions, while those that take in heat energy are endothermic. exothermicA description of a chemical reaction that releases heat energy to its surroundings.
Answer:
C
Explanation:
b/c when copper and zinc metal are addedto solution,then the solution will be consider under redox reaction
Answer:
it is endothermic change ..........