Molecules and Ions

• What is the main objective of Assignment No. 4?

  To understand accuracy and precision in measurements.
• How can numerical values or data be obtained in an experiment?

  Through measurements made during the experiment.
• What is the difference between accuracy and precision?

  Accuracy refers to how close a measurement is to the true value, while precision refers to the consistency of repeated measurements.
• What are the types of errors that can affect measurements?

  • Inaccuracy: deviation from the true value.
  • Imprecision: variability in repeated measurements.
• What is the true weight of the pebble in the dot plots?

  1. 0 g
• How can you determine if a measurement is accurate or inaccurate?

  By comparing it to the true value.
• How can you determine if a measurement is precise or imprecise?

  By assessing the consistency of repeated measurements.
• What is the average value of Student A's measurements?

  1. 971 g
• What is the true mass of the copper wire?

  1. 000 g
• Which student has the most accurate results?

  Student C, as their average is closest to the true mass.
• What are systematic errors and random errors?

  • Systematic errors: consistent, repeatable errors associated with faulty equipment or flawed experiment design.
  • Random errors: unpredictable variations in measurements due to uncontrolled variables.
• What are some possible reasons for errors in measurements?

  Faulty equipment, human error, environmental factors.
• What is the importance of significant figures in measurements?

  They express the precision of a measured quantity.
• What are significant figures?

  Digits in a number that contribute to its precision, including all non-zero digits and any zeros between them.
• What are exact numbers?

  Numbers that have no uncertainty, such as counts of objects.
• What are defined numbers?

  Numbers that are exact by definition, such as conversion factors.
• What is the rule for determining significant figures in zeros?

  Zeros can be significant or not significant depending on their position in the number.
• How many significant figures are in 4.5 inches?

  Two significant figures.
• How many significant figures are in 125.0 meters?

  Four significant figures.
• How many significant figures are in 0.001 mile?

  One significant figure.
• How many significant figures are in 25.0 grams?

  Three significant figures.
• How many significant figures are in 12.20 liters?

  Four significant figures.
• How many significant figures are in 100,000 people?

  One significant figure (unless specified otherwise).
• How many significant figures are in 205 birds?

  Three significant figures.
• How many significant figures are in 0.025?

  Two significant figures.
• How many significant figures are in 22.4?

  Three significant figures.
• How many significant figures are in 0.0404?

  Three significant figures.
• How many significant figures are in 5.50 × 10^3?

  Three significant figures.
• How many significant figures are in 40.0?

  Three significant figures.
• How many significant figures are in 0.081?

  Two significant figures.
• How many significant figures are in 129,042?

  Six significant figures.
• How many significant figures are in 4.090 × 10^-3?

  Four significant figures.
• How many significant figures are in 503?

  Three significant figures.
• How many significant figures are in 0.007?

  One significant figure.
• How many significant figures are in 4200?

  Two significant figures (unless specified otherwise).
• How many significant figures are in 3.0030?

  Five significant figures.
• How many significant figures are in 100.00?

  Five significant figures.
• How many significant figures are in 8.00 × 10^2?

  Three significant figures.
• How many significant figures are in 63,000?

  Two significant figures (unless specified otherwise).
• How many significant figures are in 6.004?

  Four significant figures.