Table of contents

1. Matter and Measurements4h 31m
2. Atoms and the Periodic Table5h 23m
3. Ionic Compounds2h 18m
4. Molecular Compounds2h 18m
5. Classification & Balancing of Chemical Reactions3h 17m
6. Chemical Reactions & Quantities2h 27m
7. Energy, Rate and Equilibrium3h 46m
8. Gases, Liquids and Solids3h 25m
9. Solutions4h 10m
10. Acids and Bases3h 29m
11. Nuclear Chemistry56m
BONUS: Lab Techniques and Procedures1h 38m
BONUS: Mathematical Operations and Functions47m
12. Introduction to Organic Chemistry1h 34m
13. Alkenes, Alkynes, and Aromatic Compounds2h 12m
14. Compounds with Oxygen or Sulfur1h 6m
15. Aldehydes and Ketones1h 1m
16. Carboxylic Acids and Their Derivatives1h 11m
17. Amines39m
18. Amino Acids and Proteins1h 51m
19. Enzymes1h 37m
20. Carbohydrates1h 41m
21. The Generation of Biochemical Energy2h 8m
22. Carbohydrate Metabolism2h 22m
23. Lipids2h 26m
24. Lipid Metabolism1h 45m
25. Protein and Amino Acid Metabolism1h 37m
26. Nucleic Acids and Protein Synthesis2h 54m

1. Matter and Measurements

Significant Figures: Precision in Measurements

GOB Chemistry

1. Matter and Measurements

Significant Figures: Precision in Measurements

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Multiple Choice

Read the length of the metal bar to the correct number of significant figures.

15 cm

15.000 cm

20 cm

15.0 cm

15.00 cm

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Verified step by step guidance

Observe the image of the pencil placed against the ruler. The pencil's tip aligns with a specific mark on the ruler.

Identify the mark on the ruler where the pencil's tip ends. In this case, it is between the 9 cm and 10 cm marks.

Determine the smallest division on the ruler. The ruler is marked in millimeters, with each centimeter divided into 10 equal parts, indicating each small division is 1 mm or 0.1 cm.

Estimate the position of the pencil's tip relative to the nearest millimeter mark. The tip appears to be exactly on the 9 cm mark, with no additional millimeters.

Express the length of the pencil with the correct number of significant figures. Since the pencil's length is exactly on the 9 cm mark, and the smallest division is 0.1 cm, the length should be recorded as 9.00 cm to reflect the precision of the measurement.