Question

How many significant figures are in the number $ 0.008 $ ?

Answer 1

Hint : Significant figures in chemistry are the mathematical values that have certainty and precision while performing mathematical operations in chemistry Significant figures, have certain rules. By following Significant figures are calculated through certain rules we can determine the above number.

Complete Step By Step Answer:
Significant figures in chemistry tell us the valuable digits in a particular mathematical operation. Significant figures are calculated through certain rules, which are:
All the digits that have no zero are significant For example, $ 32 $ have two significant figures.
The zeros that are written before non-zero digits are not significant For example, $ 0.0047 $ have two significant figures.
Zeros that are written between the non- zero digits are significant For example, $ 4.009 $ have four significant figures.
When any scientific notation is written, it is not significant.
When the exact number of anything is written, it has an infinite number of significant figures. For example, $ 30 $ bottles have significant figures.
Zeros that are written at the right hand side of the decimal are significant while if the decimal is not present then the zeros are not significant For example, $ 200 $ have $ 1 $ significant figures, while 0.200 have three significant figures.
We are given a number zero, we have to find its significant figures, since it is a zero, it has no significant figures means zero significant figures, because no decimal point is mentioned.
Here we have $ 0.008~ $ has one significant figure but $ 3 $ decimal places.
The first three zeroes are place holders i.e. $ 0.00 $.

Note :
For addition or subtraction in significant figures, the values with decimals cannot have more number of digits after the decimal written, as that in the original number. The same applies in division and multiplication of significant figures.