Question

The diameter of a certain bacterium is about 0.00005 meters
Use scientific notation

Answer 1

5 x 10^-5

Explanation:

You move the decimal 5 places to the right and this makes the exponent negative.

Answer 2

Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the 10. If the decimal is being moved to the right, the exponent will be negative. If the decimal is being moved to the left, the exponent will be positive.
so
0.00005 meters --------> 5 x 10^-5 meters