Which of the following statements about significant figures is true?

The statement that zeros between significant digits are significant is true because significant figures are used to convey the precision of a measurement. In a given number, any zeros that are sandwiched between non-zero digits must be counted as significant. For example, in the number 105, both the 1 and the 5 are non-zero digits, and the zero is placed between them, indicating that it contributes to the accuracy of the measurement. This adheres to the rules of significant figures, where the aim is to ensure that the degree of uncertainty in a measurement is accurately reflected.

In contrast, the other statements fail to adhere to the rules of significant figures. Not all zeros in a number are significant—the leading zeros before a decimal point (like those in 0.00456) are not significant. Non-zero digits are always considered significant. Lastly, the implication that only whole numbers are significant is incorrect because fractional numbers can also have significant digits based on their precision and the context in which they are presented.