Measurement and Lab Safety Unit 1 Quiz

Unit 1. Measurement

• Unit 1.1 covers writing names and abbreviations for metric or SI units used in length, volume, mass, and temperature measurements.
• Unit 1.2 involves identifying numbers as either measured or exact.
• Unit 1.3 explains how to determine the number of significant figures in a measurement.
• Unit 1.4 details how to report measurements using significant figures and appropriate units.

Lab Safety

• Students must explore eConestoga and the student portal.
• Obtain a locker, following instructions provided by myConestoga.
• Upload a picture and collect/acquire their ONE card.
• Set up their textbook and program materials.
• Complete the lab safety quiz with 100% accuracy.
• Failure to comply may prevent laboratory participation.

Learning Objectives

• Learn how to record numbers using scientific methods.
• Differentiate between measured and exact numbers.
• Understand the concept of significant figures and how to identify them correctly.
• Be able to explain the reasoning behind the specific ways we report numbers.

Measurements

• Every measurement includes a number and a unit, separated by a space.
• The metric system is used for measurements in Canada.
• Each measured quantity has a base unit.
• The common units for volume, length, mass, temperature, and time using the metric system are: liter (L), meter (m), gram (g), degree Celsius (°C), and second (s), respectively.

Length

• In chemistry, length measurements commonly use meters (m), centimeters (cm), or millimeters (mm).
• Conversion factors: 1 m = 100 cm = 1000 mm.
• The smaller the unit, the larger the numerical value.

Volume

• Volume is the three-dimensional space occupied by a substance.
• In chemistry, volume is commonly measured in liters (L) or milliliters (mL).
• Conversion factors: 1 L = 1000 mL.
• A cubic centimeter (cc) is equal in volume to a milliliter (mL).

Mass

• Mass is a measure of the quantity of material an object contains.
• It's measured using an electronic balance.
• In chemistry, mass is typically measured in grams (g) or milligrams (mg).
• Conversion factors: 1 g = 1000 mg.
• In healthcare, mass is often measured in pounds (lbs) or kilograms (kg).
• Conversion factors: 1 kg = 2.205 lbs.

Measured vs. Exact

• Measured numbers are obtained using measuring tools, and contain uncertainty.
• Exact numbers are obtained by counting items or from defined relationships between units.

Significant Figures

• All non-zero digits in a measurement are significant.
• Zeros between non-zero digits are significant.
• Zeros at the end of a decimal number are significant if they appear after a digit besides zero.
• Zeros at the beginning of a decimal number are not significant, in which they are placeholders.

Significant Figures in the Lab

• Mass measurements on electronic balances are rounded to the last reported/displayed digit.
• Temperatures are reported to one decimal place, using the estimated digit.
• Volume measurements (using graduated cylinders or beakers) are read at the bottom of the meniscus.
• Estimated digits for each of the instruments, will vary, based on the specific instrument used.

Determining Significant Figures

• Follow the rules for identifying significant zeros.
  • Zeros between non-zero digits are significant.
  • Zeros at the end of a decimal number are significant.
  • Zeros at the beginning of a decimal number are not significant.

This quiz covers essential concepts from Unit 1 on measurement, including metric unit names, identifying measured versus exact numbers, and significant figures. Additionally, it addresses important lab safety protocols, ensuring students are prepared for laboratory work. Test your knowledge and readiness for practical applications in science!