Which of the following is considered a significant figure?

The concept of significant figures is pivotal in scientific measurements as it reflects the precision of the measurement. The correct answer highlights that the final zero in the decimal portion is considered a significant figure. This is because trailing zeros in a decimal number indicate the precision of the measurement. For example, in the number 12.300, the final two zeros signify that the measurement is precise to four decimal places, which is an important detail in scientific communication.

Leading zeros, on the other hand, do not count as significant figures because they merely indicate the position of the decimal point without contributing to the accuracy of the measurement. For instance, in the number 0.0045, the leading zeros are not significant; only the '4' and '5' are.

Furthermore, all zeros in a whole number may or may not be considered significant based on their context. For example, in the number 500, the zeros might not be significant if there is no decimal shown, indicating uncertainty regarding the exactness of the measurement.

Thus, understanding how and when zeros contribute to the significance of a measurement is crucial in accurately representing data in scientific contexts.