0.00004 can be expressed as which of the following in scientific notation?

To express the number 0.00004 in scientific notation, the goal is to write it as a product of a number between 1 and 10 and a power of 10. In this case, you want to shift the decimal point in 0.00004 to the right until only one non-zero digit is to the left of the decimal.

Shifting the decimal point four places to the right transforms 0.00004 into 4.0, or simply 4. This shift corresponds to a power of ten that is negative, indicating the original position of the decimal point relative to the whole number. Since we moved the decimal four places to the right, the power of ten becomes -5 (4 can be written as 4 x 10^(-5)).

Thus, the correct expression in scientific notation for 0.00004 is 4 x 10 to the power of -5. This denotes that the original number (0.00004) is four ten-thousandths, making option B the correct choice.