After 160 years, the activity level of the sample will be 0.5 curies.
<h3>What is half-life?</h3>
Half life of any radioactive waste is the half decay of that product.
The formula is 
Where, λ is 4 cruies
λ1 is 0.5 cruies
b = 40 years
Putting the values in the equation

Thus, the correct option is 160 years.
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Supersaturated is the correct answer
Answer:
um
Explanation:
help you? you mean do it for you? nah man you can just use the calculator ;)
Think of dirt and rocks . Common as they are they do mix and they are great examples of a outside mixture. This could give u the perfect idea or picture of what u need.
Answer:
If a metal is less reactive than carbon, it can be extracted from its oxide by heating with carbon. The carbon displaces the metal from the compound, and removes the oxygen from the oxide. This leaves the metal.
Explanation: