Calculate the charge carried by `12.5xx10^(8)` electrons.

Answer

To calculate the charge carried by \( 12.5 \times 10^8 \) electrons, we can follow these steps:

### Step 1: Understand the formula for charge
The total charge \( Q \) is given by the formula:
\[ Q = N \times E \]
where:
- \( N \) is the number of electrons,
- \( E \) is the charge of one electron.

### Step 2: Identify the values
From the question:
- \( N = 12.5 \times 10^8 \) electrons
- The charge of one electron \( E = 1.6 \times 10^{-19} \) coulombs.

### Step 3: Substitute the values into the formula
Now, substituting the values into the formula:
\[ Q = (12.5 \times 10^8) \times (1.6 \times 10^{-19}) \]

### Step 4: Calculate the multiplication
First, multiply the numerical coefficients:
\[ 12.5 \times 1.6 = 20.0 \]
Next, multiply the powers of ten:
\[ 10^8 \times 10^{-19} = 10^{8 - 19} = 10^{-11} \]

### Step 5: Combine the results
Now, combine the results from the previous step:
\[ Q = 20.0 \times 10^{-11} \]

### Step 6: Convert to scientific notation
To express \( 20.0 \times 10^{-11} \) in standard scientific notation:
\[ 20.0 = 2.0 \times 10^1 \]
Thus,
\[ Q = 2.0 \times 10^1 \times 10^{-11} = 2.0 \times 10^{-10} \]

### Final Answer
The charge carried by \( 12.5 \times 10^8 \) electrons is:
\[ Q = 2.0 \times 10^{-10} \text{ coulombs} \]

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