The number 1000 has 1 significant figure if it’s written without a decimal point, which primarily counts the non-zero digits. However, if we interpret this number considering significant figures, it can vary depending on how it’s expressed.
For example:
- If we write it as 1000. (with a decimal point), it would have 4 significant figures.
- If it’s in scientific notation like 1.0 x 10^3, it would also indicate 2 significant figures.
- When the number is presented simply as ‘1000’ and without additional context, the safest interpretation is that it has 1 significant figure.
In summary, the significant figures depend on the context and notation used, but conventionally, the answer would lean towards 1 significant figure in its plain form. Therefore, we would consider option a. 1 as the answer.