Question

1. when a measuring scale is used properly to the limit of precision, the last significant digit recorded for the measurement is said to be uncertain. please explain. 8. indicate the number of significant figures in each of the following: a. 250. b. 250 c. 2.5×10² d. 250.0

Explanation:

Step1: Recall significant - figure rules

Non - zero digits are always significant. Zeros between non - zero digits are significant. Trailing zeros in a number with a decimal point are significant. Trailing zeros in a whole number without a decimal point may or may not be significant.

Step2: Analyze 250.

The number 250. has 3 significant figures. The decimal point indicates that the zero is significant.

Step3: Analyze 250

The number 250 has 2 significant figures. Without a decimal point, the trailing zero is not considered significant.

Step4: Analyze 2.5×10²

In scientific notation, all digits in the coefficient (2.5) are significant. So 2.5×10² has 2 significant figures.

Step5: Analyze 250.0

The number 250.0 has 4 significant figures. The trailing zero after the decimal point is significant.

Answer:

a. 3 significant figures
b. 2 significant figures
c. 2 significant figures
d. 4 significant figures