What are the rules in Significant Figures?
All non-zero digits are significant. For example, 6.9 has two significant figures, while 2.16 has three significant figures. The decimal place does not determine the number of significant figures. A zero becomes significant in case it comes in between non zero numbers. For example, 2.003 has four significant figures, 4.02 has three significant figures. Zeros at the beginning of a number are not significant. For example, 0.002 has one significant figure while 0.0045 has two significant figures. All zeros placed to the right of a number are significant. For example, 16.0 has three significant figures, while 16.00 has four significant figures. Zeros at the end of a number without decimal point are ambiguous. In exponential notations, the numerical portion represents the number of significant figures. For example, 0.00045 is expressed as 4.5 x 10-4 in terms of scientific notations. The number of significant figures in this number is 2, while in Avogadro’s number (6.023 x 1023) it is four.
