HELP!!! Does anyone understand???????????
1 answer:
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The question is incomplete, here is the complete question:
The half-life of a certain radioactive substance is 46 days. There are 12.6 g present initially.
When will there be less than 1 g remaining?
<u>Answer:</u> The time required for a radioactive substance to remain less than 1 gram is 168.27 days.
<u>Step-by-step explanation:</u>
All radioactive decay processes follow first order reaction.
To calculate the rate constant by given half life of the reaction, we use the equation:
where,
= half life period of the reaction = 46 days
k = rate constant = ?
Putting values in above equation, we get:
The formula used to calculate the time period for a first order reaction follows:
where,
k = rate constant =
t = time period = ? days
a = initial concentration of the reactant = 12.6 g
a - x = concentration of reactant left after time 't' = 1 g
Putting values in above equation, we get:
Hence, the time required for a radioactive substance to remain less than 1 gram is 168.27 days.
Answer:
12 feet
Step-by-step explanation:
A driveway is rectangular in shape.
Therefore we can calculate the area using the formula;
From the question;
The area,A=96 feet square
The width, W=8 feet
We substitute this values into the formula to find the length, L.
This implies that
Dividing through by 8.
Hence,the length of the driveway is 12 feet.