Question

chem ws 1a
name
sig figs
determine the number of significant figures in each of these numbers.
number significant figures number significant figures

1. 357
2. 10000
3. 51015

4.

1. 0.0007

6.

1. 5050
2. 5050.0

9.

1. 0.002110
2. 33.303
3. 170

13.

1. 0.7007
2. 0.70070
3. 4206
4. 0.02
5. 10.01
6. 0
7. 0.0

Explanation:

Step1: Non - zero digits are significant

For 357, all three digits are non - zero, so it has 3 significant figures.

Step2: Trailing zeros in a whole number without a decimal point may or may not be significant

For 10000, it is ambiguous, but usually considered 1 significant figure.

Step3: All digits in a non - zero number are significant

For 51015, all five digits are significant.

Step4: Leading zeros are not significant

For 0.0007, only the 7 is significant, so 1 significant figure.

Step5: Zeros between non - zero digits are significant

For 5050, the first zero is significant, the last zero is ambiguous, but usually considered 3 significant figures.

Step6: Trailing zeros after a decimal point are significant

For 5050.0, all five digits are significant.

Step7: Leading zeros are not significant, but trailing zeros after non - zero digits in a decimal are significant

For 0.002110, the leading zeros are not significant, and the 2110 are significant, so 4 significant figures.

Step8: All digits in a number with a decimal are significant

For 33.303, all five digits are significant.

Step9: Trailing zeros in a whole number without a decimal are ambiguous

For 170, usually considered 2 significant figures.

Step10: Zeros between non - zero digits and trailing zeros after non - zero digits in a decimal are significant

For 0.7007, all four digits are significant.

Step11: Trailing zeros after non - zero digits in a decimal are significant

For 0.70070, all five digits are significant.

Step12: All non - zero digits and zeros between non - zero digits are significant

For 4206, all four digits are significant.

Step13: Leading zeros are not significant

For 0.02, only the 2 is significant, so 1 significant figure.

Step14: All digits in a number with a decimal are significant

For 10.01, all four digits are significant.

Step15: Zero alone has 0 significant figures

For 0, 0 significant figures.

Step16: Leading zeros are not significant

For 0.0, 0 significant figures.

Answer:

1. 3
2. 1
3. 5

4.

1. 1

6.

1. 3
2. 5

9.

1. 4
2. 5
3. 2

13.

1. 4
2. 5
3. 4
4. 1
5. 4
6. 0
7. 0