Final answer:
0.036 653 has 4 significant figures.
Step-by-step explanation:
When determining the number of significant figures, we need to consider the zeros in the given number. In the case of 0.036 653, the zeros to the left of the decimal are not significant and serve as placeholders. Therefore, the significant figures in this number are 4. The number 0.036 653 has five significant figures. When counting significant figures, it's important to consider the context of zeros in the number. Zeros leading the nonzero digits in decimal numbers are not significant, as they only serve as placeholders. However, once a nonzero digit appears, subsequent digits including zeros between nonzero digits are all significant. In this case, the zeros are not leading; they are between nonzero digits and are therefore counted as significant figures.