Unit 1 Chapter 2. Common SI Units SI System is set-up so it is easy to move from one unit to another.

Slides:



Advertisements
Similar presentations
Chapter 2 – Scientific Measurement
Advertisements

SECTION 2-3. Objectives 1. Distinguish between accuracy and precision 2. Determine the number of significant figures in measurements 3. Perform mathematical.
Uncertainty and Significant Figures Cartoon courtesy of Lab-initio.com.
Chapter 2 Section 3.
Using Scientific Measurements.
Uncertainty in Measurements
Significant Figures.  All measurements are inaccurate  Precision of measuring device  Human error  Faulty technique.
Measurement & Conversions
Measurements and Calculations
Lesson Starter Look at the specifications for electronic balances. How do the instruments vary in precision? Discuss using a beaker to measure volume versus.
Chapter 1.5 Uncertainty in Measurement. Exact Numbers Values that are known exactly Numbers obtained from counting The number 1 in conversions Exactly.
Section 2.3 Measurement Reliability. Accuracy Term used with uncertainties Measure of how closely individual measurements agree with the correct or true.
The Scientific Method 1. Using and Expressing Measurements Scientific notation is written as a number between 1 and 10 multiplied by 10 raised to a power.
Significant Figures.
Measuring and Units.
Units of Measurement And their Uses DR. C.’S PRE-AP CHEMISTRY FALL 2015.
Measurements and Calculations 1. To show how very large or very small numbers can be expressed in scientific notation 2. To learn the English, metric,
Chapter 2 “Scientific Measurement” Standards for Measurement Accuracy vs. Precision Significant Figures.
Reliability of Measurements Chapter 2.3. Objectives  I can define and compare accuracy and precision.  I can calculate percent error to describe the.
Chapter 2 Section 3 Using Scientific Measurements.
Significant Figures, Precision, and Accuracy. Significant Figures Significant figures are numbers that mean something when reporting a value. Just because.
The Importance of measurement Scientific Notation.
Honors Chemistry I. Uncertainty in Measurement A digit that must be estimated is called uncertain. A measurement always has some degree of uncertainty.
Chapter 2: Scientific Method Cartoon courtesy of NearingZero.net.
3.1 Measurements and Their Uncertainty
Objectives Distinguish between accuracy and precision. Determine the number of significant figures in measurements. Perform mathematical operations involving.
Uncertainty in Measurement Accuracy, Precision, Error and Significant Figures.
1 Measurements. 2 Nature of Measurement Measurement - quantitative observation consisting of 2 parts Part 1 - number Part 2 - scale (unit) Part 2 - scale.
Chemical Foundations.  Every quantitative observation or measurement consists of two parts, the number and the unit.  The fundamental SI base units.
Uncertainty in Measurement
Ch. 2.1 Scientific Method. 2.1 Goals 1. Describe the purpose of the scientific method. 2. Distinguish between qualitative and quantitative observations.
Scientific Measurements. Measurements Objective Distinguish between accuracy and precision Determine the number of significant figures in measurements.
Preview Lesson Starter Objectives Accuracy and Precision Significant Figures Scientific Notation Using Sample Problems Direct Proportions Inverse Proportions.
Objectives Describe the purpose of the scientific method. Distinguish between qualitative and quantitative observations. Describe the differences between.
“Scientific Measurement”. Measurements and Their Uncertainty OBJECTIVES: Convert measurements to scientific notation.
Uncertainty in Measurement A digit that must be estimated is called uncertain. A measurement always has some degree of uncertainty. Significant figures.
Uncertainty and Significant Figures Cartoon courtesy of Lab-initio.com.
CHEMISTRY CHAPTER 2, SECTION 3. USING SCIENTIFIC MEASUREMENTS Accuracy and Precision Accuracy refers to the closeness of measurements to the correct or.
Uncertainty in Measurement A digit that must be estimated is called uncertain. A measurement always has some degree of uncertainty.
Significant Digits or Significant Figures. WHY??? The number of significant figures in a measurement is equal to the number of digits that are known with.
Ms. D CHEMISTRY Determining Significant Figures. Uncertainty in Measurement A digit that must be estimated is called uncertain. A measurement always has.
Unit 0: Observation, Measurement and Calculations Cartoon courtesy of NearingZero.net.
Chapter 2 © Houghton Mifflin Harcourt Publishing Company Accuracy and Precision Accuracy refers to the closeness of measurements to the correct or accepted.
Measurements and their Uncertainty
Units of Measurement SI units (Systeme Internationale d’Unites) were developed so that scientists could duplicate and communicate their work. Base UnitsDerived.
Measuring and Calculating Chapter 2. n Scientific method- a logical approach to solving problems n -Observation often involves making measurements and.
Chapter 2 Sec 2.3 Scientific Measurement. Vocabulary 14. accuracy 15. precision 16. percent error 17. significant figures 18. scientific notation 19.
Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter.
CH. 2 - MEASUREMENT. Observing and Collecting Data Data may be Qualitative (descriptive) Flower is red Quantitative (numerical) 100 flowers.
Scientific Measurement. Using and Expressing Measurements Measurement- a quantity that has both number and unit Scientific notation- using exponents to.
Chemistry I. Precision and Accuracy Accuracy refers to the agreement of a particular value with the true value. Precision refers to the degree of agreement.
 Importance: to ensure the accuracy of our measurements  To make sure we tell others only what we actually know based on our equipment and it’s limitations.
SIG FIGURE’S RULE SUMMARY COUNTING #’S and Conversion factors – INFINITE NONZERO DIGIT’S: ALWAYS ZERO’S: LEADING : NEVER CAPTIVE: ALWAYS TRAILING :SOMETIMES.
Chapter 1 Significant Figures.
How big is the beetle? Measure between the head and the tail!
Ch. 2 Measurements and Calculations
Unit 3: Measurement and Calculations
Chapter 2 Table of Contents Section 1 Scientific Method
Analyzing Data Chemistry Chapter 2.
Section 3-2 Uncertainty in Measurements
Accuracy and Precision
Chapter 2 Section 3-A.
Section 2.3 Uncertainty in Data
Uncertainty and Significant Figures
Uncertainty and Significant Figures
Measurements and Calculations.
Scientific Measurements
Using Scientific Measurements
Uncertainty and Significant Figures
Presentation transcript:

Unit 1 Chapter 2

Common SI Units

SI System is set-up so it is easy to move from one unit to another.

Units that arise from other SI units are called derived units.

Volume Volume is the amount of space occupied by an object. The derived SI unit is cubic meters, m 3 The cubic centimeter, cm 3, is often used The liter, L, is a non-SI unit 1 L = 1000 cm 3 1 mL = 1 cm 3

Volume

Conversion Factors A ratio derived from the equality between two different units that can be used to convert from one unit to another.

Conversion Factors

Precision and Accuracy Accuracy refers to the agreement of a particular value with the true value. Precision refers to the degree of agreement among several elements of the same quantity.

The Difference between Precision and Accuracy

Precision and Accuracy

Rules for Counting Significant Figures Nonzero integers always count as significant figures sig figs Significant Figures Consist of all digits that are known with certainty plus one final digit which is uncertain or estimated.

Rules for Counting Significant Figures - Zeros Leading zeros do not count as significant figures sig figs.

Captive zeros always count as significant figures sig figs Rules for Counting Significant Figures - Zeros

Trailing zeros are significant only if the number contains a decimal point sig figs Rules for Counting Significant Figures - Zeros

Rules for Significant Figures in Mathematical Operations Multiplication and Division: # sig figs in the result has the same number of significant figures as the number with the fewest significant figures  2.0 = Rounds to  13 (2 sig figs)

Rules for Significant Figures in Mathematical Operations Addition and Subtraction: the result has the same number of decimal places as the least precise measurement = Rounds to  22.5 (3 sig figs)

is calculated by subtracting the accepted value from the experimental value, dividing the difference by the accepted value, and then multiplying by 100. Percent Error

Direct Proportions Two quantities are in direct proportion if dividing one by the other gives a constant value. Indirect Proportions Two quantities are inversely proportional if their product is constant.