Answered

(Scientific Notation in the Real World MC)

The length of a bacterial cell is about [tex]$3 \times 10^{-6} m$[/tex], and the length of an amoeba cell is about [tex]$4.5 \times 10^{-4} m$[/tex]. How many times smaller is the bacterial cell than the amoeba cell? Answer in scientific notation with the correct number of significant digits.

A. [tex]2 \times 10^2[/tex]
B. [tex]2 \times 10^3[/tex]
C. [tex]0.7 \times 10^1[/tex]
D. [tex]6.67 \times 10^2[/tex]



Answer :

To determine how many times smaller a bacterial cell is than an amoeba cell, follow these detailed steps:

1. Identify the lengths:
- The length of a bacterial cell is: [tex]\(3 \times 10^{-6} \, \text{meters}\)[/tex]
- The length of an amoeba cell is: [tex]\(4.5 \times 10^{-4} \, \text{meters}\)[/tex]

2. Calculate the ratio of the lengths:
[tex]\[ \text{Ratio} = \frac{\text{Length of amoeba}}{\text{Length of bacterium}} \][/tex]
Plugging in the values:
[tex]\[ \text{Ratio} = \frac{4.5 \times 10^{-4}}{3 \times 10^{-6}} \][/tex]

3. Simplify the ratio:
- First, divide the numerical part:
[tex]\[ \frac{4.5}{3} = 1.5 \][/tex]
- Next, divide the powers of 10:
[tex]\[ \frac{10^{-4}}{10^{-6}} = 10^{-4 - (-6)} = 10^{-4 + 6} = 10^2 \][/tex]
- Combine the two parts:
[tex]\[ 1.5 \times 10^{2} \][/tex]

4. Express the answer in scientific notation:
The result [tex]\(1.5 \times 10^{2}\)[/tex] is already in scientific notation, and it has the correct significant digits based on the provided lengths.

So, the bacterial cell is [tex]\(1.5 \times 10^{2}\)[/tex] times smaller than the amoeba cell.

5. Compare with provided choices:
The closest choice to [tex]\(1.5 \times 10^2\)[/tex] in the given options is:
[tex]\[ \boxed{2 \times 10^2} \][/tex]