High School

Which of the following represents this number in scientific notation?

0.000000000386

A. [tex]3.86 \cdot 10^{-10}[/tex]
B. [tex]3.86 \cdot 10^{11}[/tex]
C. [tex]38.6 \cdot 10^{-10}[/tex]
D. [tex]3.86 \cdot 10^{10}[/tex]

Answer :

To express the number 0.000000000386 in scientific notation, you need to follow these steps:

1. Identify the significant digits: In the number 0.000000000386, the significant digits are 3.86.

2. Move the decimal point: To write the number in scientific notation, you move the decimal point to the right until you have a number between 1 and 10. For 0.000000000386, you move the decimal point 10 places to the right, resulting in 3.86.

3. Determine the exponent: Since you moved the decimal point 10 places to the right, the exponent will be negative, indicating the initial number was very small. The exponent is -10.

4. Write in scientific notation: Combine the significant digits and the exponent to write the number in scientific notation. It becomes [tex]\(3.86 \times 10^{-10}\)[/tex].

Among the given choices, the correct representation of 0.000000000386 in scientific notation is [tex]\(3.86 \times 10^{-10}\)[/tex].