Final answer:
The diameter of a human cell nucleus in standard notation is 0.000007 meters, converting from the scientific notation 7 x 10^-6 meters.
Step-by-step explanation:
The diameter of a human cell nucleus is about 7 x 10^-6 meters. When converting from scientific notation to standard notation, we move the decimal point six places to the left (because the exponent on the 10 is -6), which gives us 0.000007 meters. Therefore, the length of the nucleus diameter in standard notation is 0.000007 meters.