Final answer:
To convert the diameter of an E. coli bacterium from scientific notation (5 x 10^-7 meters) to standard decimal notation, you move the decimal point seven places to the left to get 0.0000005 meters.
Step-by-step explanation:
An E. coli bacterium has a diameter of about 5 x 10-7 meters. To write this measurement in standard decimal notation, we need to convert it from scientific notation. The expression 5 x 10-7 means that you need to move the decimal point in the number 5 seven places to the left because the exponent is negative. This gives us a value of 0.0000005 meters