ΙΣΤΟΡΙΑ ΤΗΣ ΣΥΓΧΡΟΝΗΣ ΕΠΙΣΤΗΜΗΣ

ΙΣΤΟΡΙΑ ΤΗΣ ΣΥΓΧΡΟΝΗΣ ΕΠΙΣΤΗΜΗΣ 

In 1905—his extraordinary 𝘈𝘯𝘯𝘶𝘴 𝘔𝘪𝘳𝘢𝘣𝘪𝘭𝘪𝘴—Albert Einstein completed and submitted his doctoral dissertation to the University of Zurich, titled “𝘈 𝘕𝘦𝘸 𝘋𝘦𝘵𝘦𝘳𝘮𝘪𝘯𝘢𝘵𝘪𝘰𝘯 𝘰𝘧 𝘔𝘰𝘭𝘦𝘤𝘶𝘭𝘢𝘳 𝘋𝘪𝘮𝘦𝘯𝘴𝘪𝘰𝘯𝘴.”

In this work, Einstein developed a method to estimate the size of molecules and calculate Avogadro’s number by analyzing how dissolved sugar affects the viscosity of a liquid. His results provided strong quantitative support for the existence of atoms and molecules—at a time when their physical reality was still debated.

The dissertation was accepted in July 1905, the same year Einstein published four groundbreaking papers that would transform physics. Though often overshadowed by his work on relativity and the photoelectric effect (for which he won the Nobel Prize), his doctoral research played a crucial role in establishing atomic theory on firm experimental footing.

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Επισκόπηση AΙ

Avogadro’s number (also known as the Avogadro constant) is the exact number of constituent particles—such as atoms, molecules, or ions—found in one mole of a substance. Its exact defined value is \(6.02214076 \times 10^{23}\). [1, 2, 3, 4]

The Concept

Because atoms and molecules are too small to count or measure individually in a laboratory setting, chemists use the mole as a bridge between the microscopic and macroscopic worlds. [1, 2]

Think of it like a "dozen"—whereas a dozen always equals 12 items, a mole always equals \(6.022 \times 10^{23}\) items. [1, 2]

• 1 dozen eggs = 12 eggs
• 1 mole of Carbon = \(6.022 \times 10^{23}\) Carbon atoms
• 1 mole of water = \(6.022 \times 10^{23}\) water molecules [1]