Download The History of the Periodic Table

TEACHER’S GUIDE
TEACHER’S GUIDE
TEACHER’S GUIDE
Focus Questions
Suggested Internet Resources
1. Regarding matter, how did the beliefs of Democritus compare with
those that were popularized by Aristotle?
2.What is cinnabar? Name the components of cinnabar and describe
some of their properties.
3.What element was known to the ancients as “brimstone”? What is this
element used for?
4. Describe alchemy.Was it a true science? Explain how it was replaced.
5.What is the “Law of Definite Proportions?”
6. How did the invention of the spectroscope in 1859 change the science
of chemistry?
7.What is the Law of the Conservation of Matter? Who developed it?
8.What is an element? How has the definition changed over time?
9. Describe the structure of an atom.
10. How has the periodic table changed since 1869?
Periodically, Internet Resources are updated on our web site at
www.LibraryVideo.com
• www.chemheritage.org/EducationalServices/
chemach/tpg/tpg.html
This site developed by the Chemical Heritage Foundation profiles the
accomplishments of many scientific pioneers, including Antoine Lavoisier.
• www.webelements.com/
Web Elements features an interactive periodic table which allows users to
learn more about the elements.
• www.science-education.org/
“The Science Center”, sponsored by the Chlorine Council, provides a
wealth of information about the elements on this Web site.
Follow-up Activities
• Encourage a group of students to learn about the dramatic life and death
of Antoine Lavoisier and his wife during the French Revolution. Have
other groups research the rich history of alchemy throughout the world.
Introduce one group to the Islamic alchemist Abu Musa Jabir Ibn
Hayyan, known as Geber in Europe. He built on the ideas of Aristotle,
adding the concept of "natures," which he listed as hotness, coldness,
dryness, and wetness. Point other groups to Chinese and Hindu
alchemists, and have them create posters to share.
• Challenge students to memorize elements' names and symbols and
create a memory card game to play.
• Have each student choose a family of elements to research: alkali metals,
alkaline earth metals, transition metals, other metals, rare earth elements,
metalloids, other non-metals, halogens, noble gases. Have them report
back to the class with information on when the elements in their family
were discovered, where there are in nature, how they are used by
people, and properties that they share.
Suggested Print Resources
• Boyle, Robert. The Sceptical Chymist. Dover Publications, Mineola, NY;
2003.
• Cobb, Cathy. Creations of Fire: Chemistry's Lively History from Alchemy
to the Atomic Age. Perseus Publishing, New York, NY; 2002.
• Emsley, John. The 13th Element: The Sordid Tale of Murder, Fire, and
Phosphorus . John Wiley & Sons, New York, NY; 2002.
• Gordin, Michael. A Well-Ordered Thing: Dmitrii Mendeleev and the
Shadow of the Periodic Table. Basic Books, New York, NY; 2004.
• Lavoisier,Antoine. The Elements of Chemistry. Dover Publications.
Mineola, NY; 2003.
• Morris, Richard. Last Sorcerers: The Path from Alchemy to the Periodic
Table. Joseph Henry Press,Washington, D.C.; 2003.
TEACHER’S GUIDE
Paula J. Bense, M.Ed.
Curriculum Specialist, Schlessinger Media
TITLES
• ATOMIC STRUCTURE & THE PERIODIC TABLE
• THE HISTORY OF THE PERIODIC TABLE
• PROPERTIES OF COMPOUNDS
• PROPERTIES OF ELEMENTS
• USING THE PERIODIC TABLE
Teacher’s Guides Included
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Teacher’s Guide and Program Copyright 2004 by Schlessinger Media,
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Programs produced and directed by NFL Films
All rights reserved
N6792
V7712
The History of the
Periodic Table
Grades 9 & up
critical component of successful scientific inquiry in
grades 9–12 is having students reflect on the concepts
that guide the inquiry.This five part series introduces students to the core principles of general chemistry, helping them
to establish a knowledge base to support investigation and help
develop scientific explanations.
The programs are filled with examples of observable phenomena as well as graphics and animations that clearly illustrate the
microscopic world of molecules, atoms, and subatomic particles,
and the symbolic and mathematical worlds of chemical formulas,
equations, and symbols.
Viewers explore a virtual periodic table and are shown how to
determine chemical and physical properties of the elements,
with a focus on the recognition of patterns in data. Highlighted
key points emphasize the chemistry concepts most frequently
studied in high school.
At various points throughout the programs, there are opportunities for the educator to actively involve students in the topic by
recreating the demonstrations or expanding upon the onscreen
discussion.This guide provides a brief synopsis of the program,
background on the science concepts presented in the show, discussion topics, activities, vocabulary and additional resources.
A
Program Summary
Vocabulary
Millions of different chemical substances are known.All of them are built from
simpler substances called elements, and for centuries, scientists have looked
for patterns that would explain how and why certain elements react. Our definition of the word “element” has changed as our understanding of the structure of matter has improved. Almost 25 centuries ago, the Greek philosopher
Democritus suggested that all matter was made of discrete indivisible particles
that he called atomos, meaning,“cannot be cut.” He guessed right, but his idea
of ‘atoms’ would be ignored for centuries.
The Greek thinker Aristotle did not believe in the existence of atoms. He popularized the idea that all matter on Earth was made of just four elements:
earth, wind, water, and fire. To the four Earthly elements, he added a fifth
element,“ether,” to explain the composition of heavenly bodies. He believed
that any substance on earth, such as gold, could be synthesized by combining
these basic elements in various proportions.
The idea that any form of matter could be manufactured by varying the proportions of a few basic elements had powerful appeal. It remained the dominant theory for thousands of years and was the basis of alchemy, which
brought us a step closer to the modern science of chemistry.The philosophy
of Aristotle’s elements could not be proven using experimental observations.
Errors accumulated, and alchemy ultimately proved to be a dead end.To make
further progress, these incorrect ideas would have to be discarded.
Enter the scientific method.
In 1661, the Irish alchemist Robert Boyle was the first to insist that the true
chemical elements would have to be found experimentally, rather than just
assumed.This idea was the foundation for a new science, chemistry. Boyle provided the first useful definition of the word “element.”An element, he said, was
a basic building block of all matter, so a substance that could be broken down
into simpler substances could not be an element.
About a hundred years after Boyle developed his definition, the French
chemist Antoine Lavoisier was refining the definition of “element” as a substance that could not be decomposed into simpler substances by any known
means.While compiling his theories and discoveries in textbook form was a
major contribution to the advancement of science, Lavoisier is best remembered for supporting his statements with experimental measurements.These
numerical measurements could easily be checked by other scientists and they
revealed a new pattern in the behavior of elements. In his lab, Lavoisier conducted experiment after experiment on heat and burning. He paid special
attention to the weight of ingredients in chemical reactions and the resulting
products. After comparing others' results with his own, he found that the
weight of the products of combustion always equals that of the original ingredients.This is the Law of Conservation of Mass.
(Continued)
In the early 1800s, the English chemist John Dalton proposed that elements
were actually composed of tiny particles or “atoms” that had characteristic
masses. Dalton published the first table of elements that included atomic
masses.As more and more work was done in this area, it became obvious that
there were experimental errors in many of the atomic masses that Dalton and
other workers had reported. For the rest of the 19th century, atomic masses
were continually revised and improved and new elements were rapidly being
discovered
By 1817, it was recognized that some elements could be placed into groups,
using their physical and chemical properties. Elements with closely similar
properties occur in triads, or groups of three, such as chlorine, bromine, and
iodine.These triads were a way to group elements based on observable patterns. But many elements were still unknown in the early 19th century, and
scientists didn't have enough data to convincingly show that patterns like
these held for all of the elements.
A Russian chemist, Dmitri Mendeleev, is given credit for devising the first comprehensive scheme for classifying elements in 1869.This marked the birth of
the periodic table as we know it today. (Simultaneously and independently, a
German chemist, Lothar Meyer, proposed a similar scheme.) Mendeleev made
cards for each element that included data such as element symbol and atomic
mass. He laid them out in rows and columns to look for patterns. He left gaps
in his "table" for elements that had not yet been discovered and predicted the
properties of the elements that he believed belonged there. He also placed a
few elements out of order by atomic mass, reasoning that the atomic masses
known at the time must be faulty. Eventually, all of the gaps that Mendeleev
left in his table were filled with newly discovered elements, and his predictions were right! The accurate prediction of the properties of undiscovered
elements was powerful evidence that the table correctly described patterns in
element properties. However, as more elements were discovered, problems
began to arise in the table if the elements were ordered by increasing atomic
mass.
In the modern version of the periodic table, this problem has been solved by
ordering the elements by atomic number instead of atomic mass.The modern
periodic table lists elements in order of atomic number, and shows clearly
repeating patterns in the physical and chemical properties of the elements.
The position of an element on the table reveals a wealth of information about
its properties and its behavior in chemical reactions.The modern Periodic
Table has seven rows, called periods. Every element in a period has the same
number of electron shells (orbit levels).There are 18 columns, called groups.
Every element in a group has similar properties and the same number of electrons in its outer shell. Each box in the table has information about an
element: its chemical symbol (a one or two lettercode), its atomic number
(number of protons), and its atomic mass (the total number of protons and
neutrons).
atoms — The small particles that make up matter, consisting of a nucleus
containing protons and neutrons surrounded by electrons.
atomic mass — The average mass of all the atoms of an element atomic
mass units (amu) for all possible isotopes of that element.Atomic mass is
found by adding the number of protons and neutrons.
atomic number — The number of protons in the nucleus of an atom of
an element.The atomic number also gives the number of electrons in a
neutral atom and is a natural criterion for ordering the elements on the
periodic table.All the atoms of an element have the same atomic number.
chemical symbol — An element’s one or two letter code representing its
name.
chemistry —The science that describes the behavior of substances as
they undergo physical and chemical changes.
electrons — The negatively charged particles that orbit the nucleus of
every atom.
elements — Unique pure substances that are comprised of atoms having
the same properties and the same number of protons.
Law of Conservation of Matter — The scientific principle that states
there is no change in total mass during a chemical change.The demonstration of conservation of mass by Antoine Lavoisier in the late 18th century
was a milestone in the development of modern chemistry.
Law of Definite Proportions — The scientific principle that states that,
in a pure compound, the elements combine in definite proportions to
each other.This principle allowed chemist John Dalton to develop the
atomic theory in the early 1800s.
Dmitri Mendeleev — (1834–1907) The 19th-century Russian chemist
who developed the first Periodic Table.
neutrons — The subatomic particles with a neutral charge located in the
nucleus of an atom.
nucleus — The center of every atom, containing positively charged
protons and neutrally charged neutrons.The number of protons in a given
nucleus distinguishes one element from another.
protons — The subatomic particles located in the nucleus of an atom that
carry a positive charge.
spectroscope — A scientific tool invented in 1859 that enabled scientists
to examine the glow emitted by elements that were heated or exposed to
an electrical charge. Every element has a different emission consisting of a
series of lines. Like a fingerprint, these “line spectra” served as a clear way
to confirm the discovery of a new element.
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