There are 118 known elements
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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Answer:
A. Optical fibers transmit light signals in high-speed communications.
Explanation:
You didn't include the image, but it probably showed light bouncing off the sides as in the diagram below.
It demonstrates how optical fibers transmit light signals in high-speed communications.
B is wrong. Satellites communicate by radio waves.
C is wrong. Solar cells convert light energy to
D is wrong. Power plants transmit electrical energy to homes through copper wires.
Answer:
vov-nhmb-snm
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