Chapter 2 Measurement and Problem Solving

Lecture 02

Presenter Dr. Luis Bello

Videos I recommend to watch

Today Topic videos

Scientific Notation https://youtu.be/Dme-G4rc6NI

Significant figures https://youtu.be/7b60RZqut0U

International System and Units conversion https://youtu.be/8XoDCewJ-z0

https://youtu.be/0JvFeT22ORU

Density https://youtu.be/-EZmXVOSa20

What is scientific notation and why do we use it?

Working with very large or small quantities usually ends up being quite complicated. Scientific notation is a way to write numbers in an abbreviated way, making it easier to work with these numbers.

Multiple Choice

7.82 x 10^-6 is an example of scientific notation. The exponent of -6 tells you your number will be very ________.

• Large
• Small
• Basic

Multiple Choice

Change from standard form to scientific notation: 12,000,000

• 12.0  x  10⁷
• 0.12  x  10⁷
• 1.2  x  10⁶
• 1.2  x  10⁷

Multiple Choice

Change from standard form to scientific notation:  0.000398

• 39.8  x  10^-5
• 3.98  x  10^-5
• 3.98  x  10^-4
• 39.8  x  10^-6

Sig. Fig.

It is important to use the correct number of significant numbers when reporting the results of an experiment because they indicate the accuracy of the measurements. Significant numbers in measurement are those that provide fundamental information about uncertainty or accuracy of measurement.

Multiple Choice

The number 0.0069 has...

• 2 sigfigs

• 4 sigfigs

• 5 sigfigs

• 1 sigfig

Multiple Choice

The number 5003.20 has ....

• 4 sigfigs

• 2 sigfigs, same as decimal places

• 6 sigfigs

Multiple Choice

How many significant figures does the following number have: 0.998005

• 9
• 10
• 6
• 5

Multiple Choice

How many significant figures does 1.90 × 10⁸ have?

• 3
• 4
• 6
• 8

Multiple Choice

Which is the proper way to report this calculation?

12.345 + 3.72

• 16.065 because 12.345 has the most sigfigs

• 16.1 because 3.72 has the fewest sigfigs

• 16.07 because 3.72 has the fewest decimal places

• 16 because you always round to the nearest whole number

Multiple Choice

1145.678 + 4.56 + 623.9789 + 78.1 = ? (Use significant figures!)

• 1853.3
• 2000
• 1952.3
• 1852.3

Multiple Choice

6.42 - 2.5 =

• 3.92

• 3.9

• 4.0

• 4

Multiple Choice

2.0 x 3.1 x 5.67 =

• 35.154

• 35.15

• 35.2

• 35

Multiple Choice

10.00 / 2.5

• 4

• 4.0

• 4.00

Multiple Choice

The number of SigFigs in the answer of the following: 12.34 x 567

• 3

• 4

• 3.5

• 7

Multiple Choice

Round to the nearest ten

587

• 600

• 580

• 590

• 500

Multiple Choice

Round to the nearest hundred

815

• 800

• 820

• 810

• 900

Multiple Choice

Round to the nearest hundredth

51.016

• 51.000

• 51.020

• 51.010

• 52.026

Multiple Choice

Round to the nearest whole number (ones)

45.2

• 50.0

• 55.0

• 45.0

• 55.2

SI

The International System of Units (SI, abbreviated from the French Système international (d'unités)) is the modern form of the metric system. It is the only system of measurement with official status in nearly every country in the world.

It comprises a coherent system of units of measurement starting with seven base units, which are the second (the unit of time with the symbol s), meter (length, m), kilogram (mass, kg), ampere (electric current, A), kelvin (thermodynamic temperature, K), mole (amount of substance, mol), and candela (luminous intensity, cd).

The system allows for an unlimited number of additional units, called derived units.