In scientific notation, the radius of each bacterium in a petri dish is 3.15 × 10-7 meter. The radius of the bacterium written as a decimal number in standard form is meters.

0.000000315m

Explanation:

Radius of each bacterium in a petri dish

= 3.15 × 10^-7

According to the law of indices,

10^-7 = 1/10^7 = 1/10000000

Therefore, 3.15 × 10^-7 will then be:

= 3.15 × 1/10000000

= 0.000000315m

Therefore, the radius of the bacterium written as a decimal number in standard form will be 0.000000315m