Answer:
5
Step-by-step explanation:
It's the one that's missing.
Hope I helped!
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Answer:
We can use the sample about 42 days.
Step-by-step explanation:
Decay Equation:



Integrating both sides


When t=0, N=
= initial amount




.......(1)
.........(2)
Logarithm:
130 days is the half-life of the given radioactive element.
For half life,
,
days.
we plug all values in equation (1)






We need to find the time when the sample remains 80% of its original.







We can use the sample about 42 days.
Answer: 31 and 33
Step-by-step explanation: THIS IS NOT A VERIFIED ANSWER SO IF ITS WRONG IM AM TERIBLY SORRY BUT CAN I PLEASE GET BRAINLIEST
So first we see if increase or decrease
180<210
it is increase
then we assume that
percent change
find how much change took place
210-180=30
30/180=x% change
percent means parts out ofo 100s so x%=x/100
30/180=x/100
multiply both sides by 100
3000/180=x
16.66666=x
answe ris 16.6%