Chemistry - Significant Figures and Scientific Notation

How many significant figures are in the number 45.246?

Five, since all nonzero digits are significant.

How many significant figures are in the number 37,008?

Five, since all zeros between nonzero digits are significant.

How many significant figures are in the number 0.00037?

Two, since leading zeros are not significant.

The number 450 contains how many significant figures?

Two, since the decimal point was not written after the 0. This implies that the 0 after the 5 was not measured.

The number 450. contains how many significant figures?

Three, since the decimal point was written after the 0. This implies that the 0 after the 5 was measured. Trailing zeros for a whole number that ends with a decimal point are significant.

How many significant figures are in the number 37.0000?

Six, since trailing zeros to the right of the decimal place are significant.

How many significant figures are in the expression 10 chairs?

Infinite, since exact numbers have an infinite number of significant figures.

How many significant figures are in pi?

Infinite, since irrationally defined numbers have an infinite number of significant figures.

How many significant figures are in the scientific notation 6.50 × 10⁹?

Three. 10 and its exponent does not count towards the number of significant figures in a scientific notation.

Addition/Subtraction SigFig Rule

The resulting value will have the same number of decimal places as the value with the fewest number of decimal places.

How many significant figures will the sum of 43.6 and 37.22 have?

Three, since the resulting value in addition/subtraction will have the same number of decimal places as the value with the fewest number of decimal places.

Multiplication/Division SigFig Rule

The resulting value will have the same number of total significant figures as the value with the fewest number of significant figures.

How many significant figures does the product of 76.142 and 53.22 have?

Four, since the resulting value in multiplication/division will have the same number of total significant figures as the value with the fewest number of significant figures.

1.25 × 9.000 = ?
Write the answer in scientific notation.

1.13 × 10³

0.00666 × 321 = ?
Write the answer in scientific notation.

2.14 × 10⁰

13.77 + 908.226 + 515 = ?
Write the answer in scientific notation.

1.437×10³

217 / 903 = ?
Write the answer in scientific notation.

2.40 × 10^-1

2(1.008 g) + 15.99 g = ?

18.01g
Perform multiplication first.

2 (1.008 g 4 sig figs) = 2.016 g 4 sig figs

The number with the least number of significant figures is 1.008 g; the number 2 is an exact number and therefore has an infinite number of significant figures.

Then, perform the addition.

2.016 g thousandths place + 15.99 g hundredths place (least precise) = 18.006 g

Round the final answer.

Round the final answer to the hundredths place since 15.99 has its farthest right significant figure in the hundredths place (least precise).

(118.7g/2)-35.5g = ?

23.9g
Perform division first.

(118.7/2) - 35.5 = 4 sig figs = 59.35 g 4 sig figs

The number with the least number of significant figures is 118.7 g; the number 2 is an exact number and therefore has an infinite number of significant figures.

Perform subtraction next.

59.35 g hundredths place − 35.5 g tenths place (least precise) = 23.85 g

Round the final answer.

Round the final answer to the tenths place based on 35.5 g.

5(1.008s) - 10.66 s

-5.62s

How many zeros are in 1.5 × 10¹¹?

10. The number is 150, 000, 000, 000.