Question
Question An element with mass 210 grams decays by 8.3% per minute. How much of the element is remaining after 15 minutes, to the nearest 10th of a gram? Answer Attemptiout of 2
Answer
4.3
(251 Votes)
Benjamin
Master · Tutor for 5 years
Answer
### 60.6 grams
Explanation
## Step 1: Identify the decay formula### The decay of an element can be modeled using the exponential decay formula:
, where
is the mass at time
,
is the initial mass,
is the decay constant, and
is time.## Step 2: Determine the decay constant### The decay rate is given as 8.3% per minute, which means
per minute. This is because
and here
.## Step 3: Apply the formula to find the remaining mass after 15 minutes### Using the formula with
grams,
, and
minutes, we get:
M(15) = 210 \cdot e^{-0.083 \cdot 15}
## Step 4: Calculate the exponent### Calculate the exponent value:
-0.083 \cdot 15 = -1.245
## Step 5: Compute the remaining mass### Substitute the exponent back into the formula and compute:
M(15) = 210 \cdot e^{-1.245} \approx 210 \cdot 0.2887 = 60.627 \text{ grams}
## Step 6: Round the result### Round to the nearest tenth of a gram:
grams.