Chemistry - Scientific Notation and Significant Figures

Scientific Notation - (a) define it and (b) explain what purpose it serves.

(a) It is a way of writing a value as the product of a number, a, between one and ten, and a power of ten, n; a x 10ⁿ; (b) it provides a convenient way of writing really large or really small numbers.

Significant Figures - (a) define it and (b) explain what purpose it serves.

Significant digits are the ones that are known for a measurement plus one estimated digit. They are how scientists indicate the precision of a measurement.

Write 491,000,000,000 m in scientific notation. Use the same number of significant figures as the number above has.

=4.91 x 10¹¹ m

A sample of oxygen gas has a mass of 0.000075 g. What is its mass correctly written in scientific notation? Use the same number of significant figures as the number above has.

7.5 x 10⁻⁵ g

A sample of argon gas has a mass of 3.400242 x 10⁻⁴ mg. It is combined with a sample of helium gas having a mass of 2.300 x 10⁻⁶ mg. What is the mass of the total sample in scientific notation? Use the correct number of significant figures in your answer.

342.3 x 10⁻⁶ mg

Joseph subtracts 2.0 kg from 88.645 kg. What is the correct answer, to the correct number of significant figures?

86.6 kg

What is the correct way to write 1,550,000,000 in scientific notation? Use the same number of significant figures as the number above has.

1.55 x 10⁻⁹

Which is the correct way to write 602,200,000,000,000,000,000,000 in scientific notation? Use the same number of significant figures as the number above has.

6.022 x 10²³

Which number is equal to 0.00000906060000 in scientific notation? Use the same number of significant figures as the number above has.

9.06060000 x 10⁻⁶

Andi performs the calculation that is shown below.

(2.06)(1.743)(1.0)

How should the answer be reported using the correct number of significant figures?

3.6

(3.5 × 10⁻⁶) / (5 × 10⁻²)

Use the correct number of significant figures.

7 × 10⁻⁵

Challenge problem: (6 x 10⁻⁷)(5 x 10⁹) + (9.01 x 10³)

Use the correct number of significant figures.

1 x 10⁴