To explore the early history of the periodic table and how it contributed to the understanding of atoms.
This lesson is the third of a five-part series that will broaden and enhance students’ understanding of the atom and the history of its discovery and development from ancient to modern times.
The History of the Atom 1: The Ancient Greeks examines the ancient Greeks’ theories about the atom. The History of the Atom 2: Dalton explores early milestones in atomic theory and the role of John Dalton. This lesson reviews the early development of the periodic table and its impact on atomic thought. The History of the Atom 4: J.J. Thomson analyzes the evolution of modern ideas on the inner workings of atoms and J.J. Thomson’s contributions. The History of the Atom 5: The Modern Theory investigates the development of modern atomic theory.
Greek philosophers Leucippus and Democritus first developed the concept of the atom in the 5th century B.C.E. However, since Aristotle and other prominent thinkers of the time strongly opposed their idea of the atom, their theory was overlooked and essentially buried until the 16th and 17th centuries. In time, Lavoisier’s groundbreaking 18th-century experiments accurately measured all substances involved in the burning process, proving that “when substances burn, there is no net gain or loss of weight.” Lavoisier established the science of modern chemistry, which gained greater acceptance because of the efforts of John Dalton, who modernized the ancient Greek ideas of element, atom, compound, and molecule and provided a means of explaining chemical reactions in quantitative terms. (Science for All Americans, pp. 153–155.)
As this series of lessons explores further discoveries in the configuration, bonding, and inner structures of atoms, students will come to realize how much more refined, modernized, and scientific atomic theory has become since the critical breakthroughs of Lavoisier and Dalton three centuries ago.
It is important for students to understand that the study of matter continues to this day, and that humankind’s millenniums-old effort to identify, understand, and document the nature of matter eventually created modern sciences like chemistry and continues to lead to countless, purposeful technological advancements and inventions—like the TVs and computers that make the quality of life for humankind more and more fulfilling, convenient, and sometimes troubling. Students should also come to realize that, over time, the ancients’ ideas of matter were often proven inaccurate through modern science.
In middle school, students should have become familiar with the early theories of matter and how they led to the work of Lavoisier and the birth of modern chemistry. This awareness will help students better understand the importance of John Dalton’s work, and how he ultimately ushered in “the consistent use of language, scientific classification, and symbols in establishing the modern science of chemistry.” (Benchmarks for Science Literacy, pp. 250–251.)
Ideas in this lesson are also related to concepts found in these Common Core State Standards:
- CCSS.ELA-Literacy.RST.9-10.1 Cite specific textual evidence to support analysis of science and technical texts, attending to the precise details of explanations or descriptions.
- CCSS.ELA-Literacy.RST.9-10.2 Determine the central ideas or conclusions of a text; trace the text’s explanation or depiction of a complex process, phenomenon, or concept; provide an accurate summary of the text.
This lesson should take two 45-minute class periods.
Depending on needs and goals, students may use the Printable Periodic Table to enhance their learning experience.
Review the ideas of Dalton highlighted in the second lesson. Before Dalton, students read about the early modern atomic and pre-chemistry ideas and findings of Galileo, Bacon, Boyle, and Newton. Briefly review key points in this history. Explain to students that, after learning about these key contributions to the history and evolution of atomic theory, they should be able to appreciate the long, natural, progressive, cumulative human process that has been involved in discovering the laws of nature through science; in this case, atomism.
After completing the second lesson, students need to be able to make a distinction between physical and chemical atomism. Explain to them that Dalton developed his chemical atomic theory by borrowing and scrutinizing the ideas and data of numerous scientific figures dating back to the ancients and through his own considerable studies and experiments involving vapor pressure, gas solubility, and gas mixtures.
Point out that Dalton sought to prove that “the sizes of particles making up different gases must be different.” He wanted to determine the sizes, weights, and numbers of all chemical particles involved in chemical reactions. He succeeded in becoming the first to (1) create a system determining the atomic weights of elements, and (2) use standard symbols for elements. One of his key concepts—“that chemical reactions can be explained by the union and separation of atoms and that these atoms have characteristic properties”—went on to become one of the key principles of modern physical science.
Make sure that students have a working knowledge of the four basic ideas of Dalton’s chemical atomic theory as prerequisite for this lesson: (1) chemical elements are made of atoms; (2) the atoms of an element are identical in their masses [proven incorrect; discovery of isotopes]; (3) atoms of different elements have different masses; and (4) atoms only combine in small, whole number ratios such as 1:1, 1:2, 2:3, and so on. Ideally, students should be able to identify and differentiate the laws of conservation of mass, definite proportions, and multiple proportions—and how they relate to and support the ideas of his theory.
Overall, during the developmental history of atomic theory, help students to see Dalton’s landmark work as officially advancing the modernization of the scientific approach in the study of atomism. Instead of theorizing as the ancients did, Dalton used empirical and systematic investigation to study and break down the atom. As a result, modern science’s highly empirical approach has led to greater scientific organization (the periodic table) and greater discoveries about the structure, bonding, and inner workings of atoms, which is the benchmark and focus of the final lessons of this series.
This part of the lesson will introduce and focus on the early history of the periodic table (in the context of the development of our modern atomic theory). NOTE: This is not an introduction to the periodic table; students should already be familiar with and know how to use a periodic table.
Students should use their Periodic Table student esheet to go to and read A Brief History of the Development of Periodic Table. Students should read this chronological history as a way to orient them to the key developments in the history of the periodic table.
Afterward, direct students to complete the Periodic Table Timeline student sheet by filling in the key dates, facts, figures, and events that make up the periodic table’s nearly 300 years of historical development. Remind students that they will be responsible for assessing the significance of each event in the timeline. A Periodic Table Timeline teacher sheet with answers is also provided.
After completing their timelines, ask students to address these questions and other questions in an open class discussion of the reading:
- Explain the significance of each of the key events on the timeline.
- In brief, how did Mendeleev create his periodic table?
- What made Mendeleev’s periodic table more widely accepted than others?
- (Highlight the Law of Triads, Law of Octaves, etc.)
- (He first organized known elements with similar properties into “families” and then identified patterns in the properties and weight of halogens and alkali and alkaline metals. To broaden this pattern, Mendeleev created cards for each of the 63 elements, noting their symbols, weights, and properties on each. When he arranged the cards in order of ascending atomic weight grouping elements of similar properties together, the periodic table was formed.)
- (His version reflected periodic “similarities not only in small units such as the triads, but showed similarities in an entire network of vertical, horizontal, and diagonal relationships” among elements. His later “changes,” “gaps,” and predictions of “unknown” elements also made his periodic table the most accurate representation to-date.)
NOTE: This reading refers to Mendeleev’s periodic law, but does not define it. Ask students if they know what it is, since it is relevant to this lesson and the next.
Begin the class with a brief review of what they learned in Part One about the history of the periodic table. Ask questions covering the material (without letting students take out their timelines or notes).
Next, inform students that they will read sections from another more detailed history of the periodic table, and that they will be responsible for answering questions regarding the role of the periodic table in the development of modern atomic theory.
Students should read Visual Elements: Development of the Periodic Table and answer the questions on the Development of the Periodic Table student sheet You will notice that this Web resource—like the one in Part One—covers the same general figures and events in the development of the periodic table, but in more depth and detail.
After students read the material, hold an open-class discussion, touching on the comprehension and analysis questions found on the Development of the Periodic Table teacher sheet. If you prefer, use these questions as a basis for a worksheet, quiz, or pair work exercise.
Offer the class a brief summation by discussing how more than 700 versions of the periodic table have been published since Mendeleev, and yet his updated, “modern long form” (IIIC3-4) of the table continues to be the standard today.
In assessing the significance of the periodic table in science, you also may wish to discuss with students how the periodic table can act as a very useful framework for classifying information. Periodic tables with data of use to chemists, physicists, spectroscopists, metallurgists, and others have been produced. Some tables have up to 20 pieces of numerical data in each box. The periodic table is, and probably always will be, the trademark of inorganic chemistry. Its beauty, its simplicity, and its coding of fundamental laws of nature are unsurpassed.
Specifically address how the key “discoveries” in the history of the periodic table have helped advance modern atomic theory. Elaborate on how the natural, concrete “framework” of chemical elements that Mendeleev and others gradually “discovered” continues to provide a sound, systematic basis by which scientists can further their investigation on the nature, properties, bonding, and structure of atoms—not to mention the future applications humanity can gain from this ongoing endeavor.
After the review and discussion of the material in both classes, instruct students to put their notes and timelines away and take out a sheet of paper. Then direct them to write an essay or report explaining (a) how the periodic table developed, (b) how it represents a body of knowledge, and (c) how it has been helpful in the development of modern atomic theory. After this lesson, students should be able to explain (a) and (b), while (c) will help to prime them for the last two lessons in this series.
Follow this lesson with the fourth and fifth lessons in the Science NetLinks series on the history of the atom: The History of the Atom 4: J.J. Thomson and The History of the Atom 5: The Modern Theory.
Students can read more about the history of the periodic table at History of the Development of the Periodic Table of Elements.