Answer:

Step-by-step explanation:
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Answer:
<em><u>about 23 units</u></em>
Step-by-step explanation:
The percentage of the radioactive isotope left is 25.0000%.
<h3>What is the half life?</h3>
The half life of a radioactive isotope is the time that will elapse before only half of the number of original isotopes will remain.
Now;
We are told that;
Half life (t1/2) = 55 days
Time taken (t) = 115 days
Ratio of isotope remaining = N/No
Thus;
N/No = (1/2)^t/t1/2
N/No = (1/2)^115/55
N/No = (1/2)^2
N/No =1/4
Hence, the percentage = 1/4 * 100/1 = 25.0000%
Learn more about half life of an isotope:brainly.com/question/16387602
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Answer:
It’s going by 2
Step-by-step explanation:
If you go up it goes to negative and if you go down it goes to positive
17.5 because 140 divided by 35 is 17.5 and so is 70 divided by 35.