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1. The Chemical World9m
- The Scientific Method
  9m
2. Measurement and Problem Solving2h 19m
3. Matter and Energy2h 15m
4. Atoms and Elements2h 33m
5. Molecules and Compounds1h 50m
6. Chemical Composition1h 23m
7. Chemical Reactions1h 43m
8. Quantities in Chemical Reactions1h 8m
9. Electrons in Atoms and the Periodic Table2h 32m
10. Chemical Bonding2h 10m
11 Gases2h 7m
12. Liquids, Solids, and Intermolecular Forces1h 11m
13. Solutions3h 1m
14. Acids and Bases2h 14m
15. Chemical Equilibrium1h 27m
16. Oxidation and Reduction1h 33m
17. Radioactivity and Nuclear Chemistry53m

4. Atoms and Elements

Atomic Theory

Introduction to Chemistry

4. Atoms and Elements

Atomic Theory

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Multiple Choice

Dalton used the lightest element as his standard for atomic mass. What is this element?

Helium

Oxygen

Carbon

Hydrogen

Nitrogen

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Verified step by step guidance

Understand the historical context: John Dalton, an English chemist, developed the atomic theory in the early 19th century. He needed a standard to compare the masses of different atoms.

Identify the lightest element: Dalton chose the lightest element known at the time as his standard for atomic mass. This element is hydrogen.

Recognize the significance of hydrogen: Hydrogen is the simplest and lightest element, consisting of one proton and one electron, which made it a logical choice for Dalton's standard.

Consider the alternatives: While helium, oxygen, carbon, and nitrogen are common elements, they are heavier than hydrogen and were not used by Dalton as his standard.

Conclude with Dalton's choice: Dalton's use of hydrogen as the standard for atomic mass set a precedent for future atomic mass measurements, emphasizing its fundamental role in chemistry.