Question

1. in the number 0.00450, which zeros are significant? a. the last two zeros only b. all zeros c. no zeros 3. what is the correct number of significant figures in th a. 2 b. 3 c. 4 d. 5 4. in the number 0.00450, which zeros are significant? a. the last two zeros only b. all zeros c. no zeros 5. which measurement has three significant figures? a. 0.0304 b. 3.40 c. 0.030 d. 3000 section 2: determine the number of significant figures in each a. 0.00712 b. 500 c. 8000. d. 5.00 e. 4000123 section 3: make the following calculations and apply the signific a) 47.1 + 24.32 b) 0.12 c) 5000 x 10. d) 5000. e) 45.6 / 2.1 f) 31.0 / 2

Explanation:

Step1: Recall significant - figure rules

Leading zeros (zeros before non - zero digits) are not significant. Trailing zeros (zeros after non - zero digits) are significant if there is a decimal point.

Step2: Analyze 0.00450

The leading zeros (the three zeros before 4) are not significant. The last zero is significant because there is a decimal point. So, the last two zeros are significant.

Step3: Determine significant figures in 0.00450

The significant figures are 4, 5, and the last 0. So, there are 3 significant figures.

Step4: Check each option for three - significant - figure measurements

• For 0.0304: The leading zero is not significant, and it has three significant figures (3, 0, 4).
• For 3.40: The trailing zero is significant, and it has three significant figures (3, 4, 0).
• For 0.030: The leading zero is not significant, and it has two significant figures (3, 0).
• For 3000: Without a decimal point, the trailing zeros are not significant, and it has 1 significant figure.

Step5: Determine significant figures in Section 2

• For 0.00712: Leading zeros are not significant, so there are 3 significant figures (7, 1, 2).
• For 500: Without a decimal point, there is 1 significant figure (5).
• For 8000.: With a decimal point, all digits are significant, so there are 4 significant figures (8, 0, 0, 0).
• For 5.00: Trailing zeros are significant, so there are 3 significant figures (5, 0, 0).
• For 4000123: All digits are significant, so there are 7 significant figures.

Step6: Perform calculations in Section 3 with significant - figure rules

• For 47.1+24.32 = 71.42. Since 47.1 has one digit after the decimal, the result should be rounded to 71.4.
• For 5000×10 = 50000. If 5000 has 1 significant figure, the result should be written as 5×10⁴. If 5000 has 4 significant figures (assuming it's measured precisely), the result is 50000.
• For 45.6÷2.1 = 21.71428571... Since 2.1 has 2 significant figures, the result should be rounded to 22.

Answer:

1. a. The last two zeros only
2. b. 3
3. a. 0.0304, b. 3.40

Section 2:
A. 3
B. 1
C. 4
D. 3
E. 7
Section 3:
A. 71.4
C. 5×10⁴ (or 50000 depending on significant - figure assumptions of 5000)
E. 22