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.

Challenge problem: (6 x 10⁻⁷)(5 x 10⁹) + (9.01 x 10³) Use the correct number of significant figures.

1 x 10⁴

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

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

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

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

(3.5 × 10⁻⁶) / (5 × 10⁻²) Use the correct number of significant figures.

7 × 10⁻⁵

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

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

86.6 kg

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

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

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.