Practice ABC 77.96.5 88.27.3 98.38 108.08.5 Temperature conversions 270 K ___ C 345 K_ C 50 C _ K -30C ___ K Known value is 7.5ml Describe.

Slides:

Advertisements

Similar presentations

Chapter 2 Significant Digits. Taking Measurements All measurements involve one estimation. If the measuring device is digital it will take the estimation.

Advertisements

The volume we read from the beaker has a reading error of +/- 1 mL.

DIFFERENTIATE: ACCURACY AND PRECISION Three targets with three arrows each to shoot. Can you hit the bull's-eye? Both accurate and precise Precise but.

Significant Figures (How Exact is Exact ?).

Using Scientific Measurements.

Significant Figures.

Significant Figures. 1.Explain what significant figures are. 2.Use Significant figures in measurements and calculations. 3.Understand how significant.

Significant (Measured) Digits Measuring with Precision.

Ch. 5 Notes---Scientific Measurement

Precision and Accuracy Uncertainty in Measurements.

Units and Standards. In science, numbers aren’t just numbers. They need a unit. We use standards for this unit. A standard is: a basis for comparison.

Data analysis (chapter 2) SI units and the metric system ▫Base units  Time (sec)  Length (m)  Mass (kg)  Temperature (Kelvin)  Derived base units.

Chapter 1.5 Uncertainty in Measurement. Exact Numbers Values that are known exactly Numbers obtained from counting The number 1 in conversions Exactly.

MEASUREMENTS. What is the difference between these two measurement rulers? Should we record the same number for each scale reading?

Video “Measurement – Every Measurement You Take” Play while students are coming into the class.

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.

measured certain digits. last digit is estimated, but IS significant. do not overstate the precision 5.23 cm cm Significant Figures (Sig Figs) (uncertain)

Warm-up: Are cell phones and ipods allowed in the classroom? What will happen to them if the teacher sees or hears one (that includes headphones)?

Video “Measurement – Every Measurement You Take” Play while students are coming into the class. Video should loop within the power point presentation but.

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

Significant Digits. Why are they important? -Show precision of instruments used -We use them ALL THE TIME in Chemistry -MUST KNOW THE RULES!!

Significant Figures. The Basics  All nonzero digits are significant  Ex: 1.2 – 2 significant digits  Ex: has 5 significant digits  Zeroes between.

Significant Figures and Scientific Notation The measuring device determines the number of significant figures a measurement has. Significant figures reflect.

Significant Figures 1.All non-zero digits are significant (2.45 has 3 SF) 2.Zeros between (sandwiched)nonzero digits are significant (303 has 3 SF)

Significant Figures in Calculations. A calculated answer cannot be more precise than the least precise measurement from which it was calculated. The answer.

Significant Digits Unit 1 – pp 56 – 59 of your book Mrs. Callender.

Accuracy and Precision Accuracy and Precision A MEASURE of your SUCCESS!

Metric system Measurements Significant figures Relationships

1 INTRODUCTION IV. Significant Figures. A. Purpose of Sig Figs Units of Measurement: Measurements indicate the magnitude of something Must include: –A.

Uncertainty in Measurement A digit that must be estimated is called uncertain. A measurement always has some degree of uncertainty. Significant figures.

Chapter 2 - Section 3 Suggested Reading Pages Using Scientific Measurements.

Accuracy & Precision & Significant Digits. Accuracy & Precision What’s difference? Accuracy – The closeness of the average of a set of measurements to.

CHEMISTRY CHAPTER 2, SECTION 3. USING SCIENTIFIC MEASUREMENTS Accuracy and Precision Accuracy refers to the closeness of measurements to the correct or.

Measurement Chapter 2. Units in Lab In lab we cannot always measure in SI units. In lab we cannot always measure in SI units.Mass Grams (g) Volume Milliliters.

Measurements and Calculations Scientific Method Units of Measurement Using Scientific Measurements.

Lesson 7 Reliability, Significant Figures and Percent Error.

Significant Figures.

Significant Figures All the digits that can be known precisely in a measurement, plus a last estimated digit.

Significant Figures Box and Dot Method. Step 1  Draw a box around all nonzero digits, beginning with the leftmost nonzero digit and ending with the rightmost.

Chapter 3.1 Accuracy and Precision Significant Figures.

1-2 Significant Figures: Rules and Calculations (Section 2.5, p )

SIG FIGURE’S RULE SUMMARY COUNTING #’S and Conversion factors – INFINITE NONZERO DIGIT’S: ALWAYS ZERO’S: LEADING : NEVER CAPTIVE: ALWAYS TRAILING :SOMETIMES.

Rules for Significant Figures

Daily Review Tell the difference between accuracy and precision. Give an example. Record 56, in scientific notation. Record in scientific.

Learning Targets I can use correct numbers of significant figures and units in both measurements and calculations. I can accurately measure mass and volume.

Math of Chem I Textbook Chapter 1 Aim:

Measurement: Significant Figures

SIG FIGURE’S RULE SUMMARY

Unit 1 Significant Figures in Measurements

Unit 2- Measurements- Significant Figures & Scientific Notation

Accuracy and Precision

GHS Enriched Chemistry Chapter 2, Section 3

Text Section 2.3 Pages

Exact and Inexact Numbers

Math Toolkit ACCURACY, PRECISION & ERROR.

Significant Figures and Percent Error

Accuracy and Precision

Who can hit the mark?.

Chapter 2 Section 3-A.

Accuracy, Precision, Percent Error, Significant Figures and Rounding

Section 2.3 Uncertainty in Data

Section 2-3 Using Measurements

Scientific Measurements

How do you determine where to round off your answers?

Significant (Measured) Digits

Presentation transcript:

Practice ABC Temperature conversions 270 K _____ C 345 K_____ C 50 C _____ K -30C _____ K Known value is 7.5ml Describe each regarding precision and accuracy Calculate the percentage error for data set A

Chapter 2 Significant Digits

Taking Measurements All measurements involve one estimation. If the measuring device is digital it will take the estimation for you. If the measuring device is scaled you must take the estimation yourself.

Electronic Measuring Devices Digital readout measuring diameter of inches. The last zero is the estimated digit.

Scaled Measuring Devices

Bottom ruler gives a measurement of 8.? cm.

Scaled Measuring Devices Measure the length of the metal using the top ruler.

How to read a meniscus.

Read the Volume in mL

Significant Digits

Rules for Significant Digits

All non-zero digits are significant.

Rules for Significant Digits All non-zero digits are significant. “Trailing” zeros after the decimal point ARE significant.

Rules for Significant Digits All non-zero digits are significant. “Trailing” zeros after the decimal point ARE significant. Zeros between significant digits are significant.

Rules for Significant Digits All non-zero digits are significant. “Trailing” zeros after the decimal point ARE significant. Zeros between significant digits are significant. All other zeros are NOT significant unless indicated to be so by having a bar placed over them.

How to Determine Significant Digits

Underline the leftmost nonzero digit.

How to Determine Significant Digits Underline the leftmost nonzero digit. Use the rules for significant digits to determine the rightmost significant digit.

How to Determine Significant Digits Underline the leftmost nonzero digit. Use the rules for significant digits to determine the rightmost significant digit. Every digit in between the leftmost and rightmost significant digits are significant as well.

Counting or Exact Numbers Counting numbers: If there are 10 people in a room there are not 9.5 or people in the room. Counting numbers are exact. Ones in Conversion Factors: 1 kilometer = 1000 meters. Exactly 1 km is equal to exactly 1000m. The 1 is considered to be an exact number and so is the Since Counting numbers are exact they have an infinite number of significant digits.

Determine the Significant Digits (Examples in Notebook) L mg µm 27.0 km 50 people cm _ 200 kg ºC 1000 mL 42, cm 225 beans dm m _ 3,200,000 µL

Determine the Significant Digits (Examples in Notebook) L mg µm km 3 50 people infinite cm 4 _ 200 kg ºC mL 1 42, cm beans infinite dm m 4 _ 3,200,000 µL 5

Math Operations with Significant Digits When multiplying and/or dividing your answer must reflect the smallest number of significant digits.

Math Operations with Significant Digits When multiplying and/or dividing your answer must reflect the smallest number of significant digits. (17.3 cm)(28 cm) = cm 2

Math Operations with Significant Digits When multiplying and/or dividing your answer must reflect the smallest number of significant digits. (17.3 cm)(28 cm) = cm 2 = 480 cm 2

Math Operations with Significant Digits When multiplying and/or dividing your answer must reflect the smallest number of significant digits. (17.3 cm)(28 cm) = cm 2 = 480 cm 2 708g ÷ 4.700ml = g/ml =

Math Operations with Significant Digits When multiplying and/or dividing your answer must reflect the smallest number of significant digits. (17.3 cm)(28 cm) = cm 2 = 480 cm 2 708g ÷ 4.700ml = g/ml = 151g/ml

Addition and/or Subtraction reflects the fewest decimal places decimal places cm − cm = 7.59 cm

Addition and/or Subtraction reflects the fewest decimal places decimal places cm − cm = 7.59 cm = 7.6 cm

Addition and/or Subtraction reflects the fewest decimal places decimal places cm − cm = 7.59 cm = 7.6 cm 8.5g g g =

Addition and/or Subtraction reflects the fewest decimal places decimal places cm − cm = 7.59 cm = 7.6 cm 8.5g g g = 10g

Addition and/or Subtraction reflects the fewest decimal places decimal places cm − cm = 7.59 cm = 7.6 cm 8.5g g g = 10g = 10.0g

Homework  Worksheet – Significant Digits & Rounding.