Final answer:
13.4 x 10¹⁵ is not correct scientific notation because the coefficient must be between 1 and 10; the correct scientific notation is 1.34 x 10¹⁶.
Step-by-step explanation:
The reason why 13.4 x 10¹⁵ is NOT a correct representation of scientific notation is Option C: The number is 10 or greater. In scientific notation, the coefficient (the number before the x 10 to the power of something) must be a number between 1 and 10. Therefore, it needs to be written in such a way that there is only one non-zero digit to the left of the decimal point.
For example, the correct scientific notation for 13.4 x 10¹⁵ would be 1.34 x 10¹⁶. The decimal point is moved one place to the left to make the number between 1 and 10, and the exponent is increased by one to compensate for this shift.
Expressing numbers in scientific notation helps make very large or very small numbers more readable and helps in calculations by standardizing the number format.