Logo
Logo
Log inSign up
Logo

Tools

AI Concept MapsAI Mind MapsAI Study NotesAI FlashcardsAI Quizzes

Resources

BlogTemplate

Info

PricingFAQTeam

info@algoreducation.com

Corso Castelfidardo 30A, Torino (TO), Italy

Algor Lab S.r.l. - Startup Innovativa - P.IVA IT12537010014

Privacy PolicyCookie PolicyTerms and Conditions

The Development of Atomic Theory

The evolution of atomic theory is marked by significant contributions from scientists like Cannizzaro, Mendeleev, and Rutherford. Cannizzaro corrected Berzelius's atomic weight errors, leading to a better understanding of molecular composition. Mendeleev's periodic table predicted elements and reinforced atomic theory. Rutherford's experiments led to the nuclear model of the atom, changing the concept of atomic structure.

See more
Open map in editor

1

5

Open map in editor

Want to create maps from your material?

Insert your material in few seconds you will have your Algor Card with maps, summaries, flashcards and quizzes.

Try Algor

Learn with Algor Education flashcards

Click on each Card to learn more about the topic

1

The concept of ______ molecules, which could split into single atoms during reactions, was advocated by Cannizzaro to address the inconsistencies in earlier atomic theories.

Click to check the answer

diatomic

2

19th-century atomic skepticism

Click to check the answer

Atoms' invisibility led to doubt about their existence; positivism influenced some scientists to dismiss atoms, favoring observable phenomena.

3

Equivalent weights vs. atoms

Click to check the answer

Equivalent weights used for predicting reactions; atoms considered theoretical until molecular structure knowledge grew.

4

Discovery of molecular internal architecture

Click to check the answer

Revealed the arrangement of atoms within molecules, providing physical evidence supporting atomic theory.

5

The phenomenon where molecules with the same ______ have different characteristics is known as ______.

Click to check the answer

chemical formulas isomerism

6

______'s experiments with silver fulminate and silver cyanate, which shared the same composition but exhibited different properties, contributed to the acknowledgment of ______ by Berzelius.

Click to check the answer

Friedrich Wöhler isomerism

7

The idea that isomers are composed of the same atoms but in different arrangements was an early concept leading to ______, proposed by ______.

Click to check the answer

structural chemistry Louis Pasteur

8

______ introduced the ______ carbon bonding model, which helped explain the spatial arrangement of atoms in molecules and the existence of various isomers.

Click to check the answer

Jacobus Henricus van 't Hoff tetrahedral

9

The ______ carbon bonding model was key in understanding why a compound like pentane could exist in ______ distinct forms.

Click to check the answer

tetrahedral three

10

Mendeleev's prediction of elements

Click to check the answer

Predicted existence and properties of scandium, gallium, germanium before discovery.

11

Periodic table's support for valency

Click to check the answer

Systematized understanding of how atoms combine, reflecting fixed valence of elements.

12

Periodic table and chemical reactivity

Click to check the answer

Provided framework for predicting how elements react chemically, aiding in reaction analysis.

13

______ motion is the random movement of particles like ______ grains in a liquid, first noted by the botanist ______ ______.

Click to check the answer

Brownian pollen Robert Brown

14

In 1905, ______ ______ provided a theoretical explanation for this motion, suggesting it was due to impacts with ______ molecules.

Click to check the answer

Albert Einstein water

15

______ ______'s experimental validation of Einstein's hypothesis offered quantitative support for the ______ ______ of gases.

Click to check the answer

Jean Perrin kinetic theory

16

The kinetic theory, which explains gas properties through molecule movement, dates back to ______ ______ in ______.

Click to check the answer

Daniel Bernoulli 1738

17

Founders of statistical mechanics

Click to check the answer

James Clerk Maxwell, Ludwig Boltzmann, Rudolf Clausius

18

Josiah Willard Gibbs's role in statistical mechanics

Click to check the answer

Extended foundational ideas, crucial for the framework's development

19

Impact of statistical mechanics on understanding matter

Click to check the answer

Explained gas behavior, heat laws, entropy; supported atomic hypothesis

20

In ______, J. J. Thomson's work with cathode rays resulted in the discovery of ______, initially termed 'corpuscles'.

Click to check the answer

1897 negatively charged particles

21

Rutherford's key experiment name

Click to check the answer

Geiger-Marsden experiment

22

Flaw in plum pudding model according to Rutherford

Click to check the answer

Failed to account for atom's mass/charge in central nucleus

23

Rutherford's atomic model analogy

Click to check the answer

Electrons orbit dense nucleus like planets orbit sun

Q&A

Here's a list of frequently asked questions on this topic

Similar Contents

Physics

Evolution of Atomic Theory

View document

Physics

The Nature of the Atomic Nucleus

View document

Physics

The Structure of the Atom: The Foundation of Matter

View document

Chemistry

The Development of Atomic Theory: From Democritus to Dalton

View document

The Development of Atomic Theory: Cannizzaro's Revisions to Berzelius

The advancement of atomic theory is a story of scientific refinement and correction. Stanislao Cannizzaro played a crucial role in addressing the inaccuracies in the atomic theories of his predecessors, such as Jöns Jacob Berzelius. Berzelius incorrectly believed that gases like hydrogen and chlorine existed as single atoms, leading to errors in chemical formulas. He observed that one volume of hydrogen reacted with one volume of chlorine to produce two volumes of hydrogen chloride, which contradicted his expectations based on his atomic hypothesis. Cannizzaro argued for the concept of diatomic molecules, such as H2 and Cl2, which could dissociate into individual atoms during reactions, thus resolving the discrepancies and advancing the understanding of molecular composition.
19th century laboratory with brass scales, laboratory glassware, Bunsen burner and porcelain mortar on wooden bench under bright window.

The Philosophical Resistance to Atomic Theory and Structural Chemistry's Triumph

In the 19th century, the invisibility of atoms led to philosophical skepticism about their existence. Influenced by positivism, which advocated for the reliance on observable phenomena, some scientists dismissed atoms as mere theoretical constructs and preferred to use equivalent weights to predict chemical reactions. However, the formulation of the periodic table and the growing knowledge of molecular structure provided compelling evidence for the reality of atoms. The decline of the equivalentist perspective was hastened by the periodic table's ability to predict the properties of elements and the discovery of the internal architecture of molecules, which reinforced the atomic theory.

Isomerism: Unraveling the Complexity of Molecular Structures

The concept of isomerism, where compounds with identical chemical formulas exhibit different properties, posed a significant challenge to non-atomic theories. Friedrich Wöhler's work with silver fulminate and silver cyanate, which had identical compositions but different properties, led to the recognition of isomerism by Berzelius. Louis Pasteur's hypothesis that isomers have the same atoms arranged differently was a precursor to structural chemistry. Jacobus Henricus van 't Hoff's tetrahedral carbon bonding model provided a framework for understanding the spatial arrangement of atoms in molecules, which explained the existence of multiple isomers, such as the three distinct forms of pentane.

Mendeleev's Periodic Table: A Cornerstone of Atomic Theory

Dmitrii Mendeleev's periodic table was instrumental in the acceptance of atomic theory. By arranging elements according to increasing atomic weight, Mendeleev revealed a periodic pattern in their properties, which allowed him to predict the existence and characteristics of then-undiscovered elements such as scandium, gallium, and germanium. The periodic table also supported the concept of valency and provided a systematic approach to understanding chemical reactivity, reinforcing the atomic theory and aligning with Dalton's law of multiple proportions.

Brownian Motion: Empirical Evidence for the Kinetic Theory of Gases

Brownian motion, the erratic movement of particles such as pollen grains suspended in a fluid, was observed by botanist Robert Brown. Albert Einstein's theoretical explanation in 1905 proposed that this motion resulted from collisions with water molecules, a hypothesis that was experimentally confirmed by Jean Perrin. Perrin's work provided quantitative evidence for the kinetic theory of gases, which posits that the properties of gases arise from the motion of their constituent molecules. This theory, dating back to Daniel Bernoulli in 1738, was now supported by empirical data, solidifying the concept of atoms and molecules in motion.

Statistical Mechanics: Solidifying the Atomic Hypothesis

Statistical mechanics emerged as a powerful framework for understanding the properties of matter based on the assumption of atomic and molecular existence. Pioneered by physicists like James Clerk Maxwell and further developed by Ludwig Boltzmann and Rudolf Clausius, statistical mechanics provided a statistical approach to the laws of thermodynamics. Josiah Willard Gibbs's contributions, though initially overlooked, were crucial in extending these ideas. The success of statistical mechanics in explaining the behavior of gases and the laws of heat and entropy lent strong support to the atomic hypothesis.

J. J. Thomson and the Discovery of the Electron

The discovery of the electron by J. J. Thomson in 1897 marked a significant evolution in atomic theory. Thomson's experiments with cathode rays led to the identification of negatively charged particles, which he called "corpuscles," now known as electrons. This discovery refuted the idea of atoms as indivisible units and led to the development of the plum pudding model, which suggested that atoms consisted of electrons dispersed within a positively charged matrix.

Rutherford's Nuclear Model: A New Understanding of the Atom

Ernest Rutherford's groundbreaking experiments, including the famous Geiger-Marsden experiment, refuted the plum pudding model. Rutherford's analysis of alpha particles deflected by thin metal foils revealed that an atom's mass and positive charge were concentrated in a central nucleus, much smaller than the atom itself. This discovery led to the nuclear model of the atom, where electrons orbit a dense nucleus, analogous to planets orbiting the sun, and revolutionized the understanding of atomic structure.