9C.2.1.1 Periodic Table
Explain the relationship of an element's position on the periodic table to its atomic number and electron configuration.
Identify and compare trends on the periodic table, including reactivity and relative sizes of atoms and ions; use the trends to explain the properties of subgroups, including metals, non-metals, alkali metals, alkaline earth metals, halogens and noble gases.
Overview
MN Standard in Lay Terms
In the Periodic Table, elements are arranged according to the number of protons (called the atomic number). This organization illustrates common recurring patterns of physical and chemical properties among the elements. (NAEP, 2009)
Big Idea
Central Concept: Repeating (periodic) patterns of physical and chemical properties occur among elements that define families with similar properties. The periodic table displays the repeating patterns, which are related to the atoms' outermost electrons.
Elements are arranged on the periodic table by increasing atomic number which designates the number of protons and electrons of an atom.
Elements have been placed into groups (families) which have similar chemical and physical properties dependent on their similar electron configurations and number of valence electrons.
The properties of elements, such as their atomic radii, display regular repeated (periodic) changes going across periods and down within groups on the table.
Trends can be used to predict the properties of elements such as reactivity and relative sizes of atoms and ions.
MN Standard Benchmarks
9C.2.1.1.1 Explain the relationship of an element's position on the periodic table to its atomic number and electron configuration.
9C.2.1.1.2 Identify and compare trends on the periodic table, including reactivity and relative sizes of atoms and ions; use the trends to explain the properties of subgroups, including metals, non-metals, alkali metals, alkaline earth metals, halogens and noble gases.
The Essentials
An element is composed of a single type of atom. When elements are listed in order according to the number of protons (called the atomic number), repeating patterns of physical and chemical properties identify families of elements with similar properties. This "Periodic Table" is a consequence of the repeating pattern of outermost electrons and their permitted energies.
4D (6-8) #6 . There are groups of elements that have similar properties, including highly reactive metals, less-reactive metals, highly reactive nonmetals (such as chlorine, fluorine, and oxygen), and some almost completely nonreactive gases (such as helium and neon). An especially important kind of reaction between substances involves combination of oxygen with something else--as in burning or rusting. Some elements don't fit into any of the categories; among them are carbon and hydrogen,essential elements of living matter.
4D / H6: When elements are listed in order by the masses of their atoms, the same sequence of properties appears over and over again in the list.
4D/M6a There are groups of elements that have similar properties, including highly reactive metals, less-reactive metals, highly reactive nonmetals (such as chlorine, fluorine, and oxygen), and some almost completely nonreactive gases (such as helium and neon).
- NAEP
P8.3 All substances are composed of one or more of approximately 100 elements. The Periodic Table organizes the elements into families of elements with similar properties.
P12.3 In the Periodic Table, elements are arranged according to the number of protons (called the atomic number). This organization illustrates commonality and patterns of physical and chemical properties among the elements.
Common Core Standards
2010 Literacy Standards - Reading Benchmarks: Literacy in Science and Technical Subjects 6-12
Integration of Knowledge and Ideas Benchmark 11.13.7.7 Integrate and evaluate multiple sources of information presented in diverse formats and media (e.g., quantitative data, video, multimedia) in order to address a question or solve a problem.
Common Core Language Arts Standards: Students can write a laboratory report in the proper form and using their knowledge of technical writing skills. Common Core Standards addressed:
RST.9-10-1. Cite specific textual evidence to support analysis of science and technical texts, attending to the precise details of explanations or directions.
RST.9-10-2. Determine the central ideas or conclusions of a text; trace the text's explanation or description of a complex process, phenomena or concept; provide an accurate summary of the text.
RST.9-10.3. Follow precisely a complex multistep procedure when carrying out experiments; taking measurements or performing technical tasks, attending to special cases or exceptions defined in the texts.
9B/H4 (ID: SMS-BMK-0609) Tables, graphs, and symbols are alternative ways of representing data and relationships that can be translated from one to another. NDSL Mathematical Standards
Misconceptions
- The elements on the periodic table are arranged by increasing atomic mass.
- A property or characteristic does not need to vary uniformly to vary periodically.
Vignette
Understanding the form and function of the Periodic Table is essential to understanding chemistry. Chemistry students at this point in their study would have an exposure to the use of the Periodic Table and the atomic mass and number of an element to determine the number of protons, neutrons and electrons of an atom. Students would also understand the arrangement of an atom's electrons in its energy levels for any element from Hydrogen to Krypton.
However, students might not have an understanding of how the Russian Chemist Dimitri Mendeleev discovered the Periodic Law or how he organized the known elements into the first Periodic Table. What follows is a snapshot of how a classroom teacher might introduce the historical development of the Periodic Table and develop student skills of classifying, organizing and observing patterns. The students also learn how the Periodic Table is a powerful tool for predicting the properties of elements using the Periodic Law and understanding trends on the Periodic Table.
Ms. Apple catches her student's attention using one of the cartoons shown below or showing the You Tube video of Tom Leherer's The Elements song. The Elements song Then she introduces the concept of classifying elements into groups and periods like the Periodic Table with her class using an activity which required students to organize cards with the properties of elements written on them into groups and periods. (Note: This activity is available as part of the ACS Chemistry In The Community curriculum or as a kit from Flinn Scientific Company Catalog No. AP6289
Students were put into small groups of about four students per group. Each student group was given a set of about 20 cards with the properties of a different element (but not the element's name) written on each. The properties on the card include the mass, density, melting point, formula with oxygen and with chloride.
Students were to discuss methods of sorting the elements into groups and periods. The elements had to be put into order of increasing mass and elements with similar properties had to be put into vertical groups. The number of elements in a group and period could vary. Students could choose any one or set of properties to place their elements into groups but they had to provide justification for their groupings. They were also to look for trends in properties going down groups or across periods.
When students were done organizing the elements into a "table" they were given the atomic number of each element. The students then were to determine the number of protons, neutrons and electrons in each element. They were to look for similarities and differences in elements in various groups. (Benchmark: 9C.2.1.1.1 Explain the relationship of an element's position on the periodic table to its atomic number and electron configuration.)
Students were also told to find where there are "missing" elements (gaps in their columns) and they were to predict the properties of the missing elements. She then showed the students a short You Tube video which detailed how Mendeleev was able to order the then known elements into his periodic table. BBC History of Mendeleev's Periodic Table
The next day Ms. Apple followed up the activity by showing the Discovery Science video called "The Elements". Discovery Science Elements Video Then during the unit Ms. Apple provided opportunities for her students to experience applications of the Periodic Law through lab activities and classroom work. Students developed skills of predicting and inference by graphing a property of elements as a function of their atomic numbers. For example, students might graph the atomic radii of elements # 1 through # 36. Students then examine trends and patterns evident by the graphs. After completing the lab activity on Graphing Periodic Properties students would be able to compare the sizes of any two elements on the periodic table based on their positions within groups and periods. An interactive version of this activity is available through Teacher Domain Interactive Graphing Periodic Properties Ms. Apple then had students examine the chemical and physical properties of elements such as the reactivity of metals. (Benchmark: 9C.2.1.1.2 Identify and compare trends on the periodic table, including reactivity and relative sizes of atoms and ions; use the trends to explain the properties of subgroups, including metals, non-metals, alkali metals, alkaline earth metals, halogens and noble gases).
For the summative unit assessment students were given the properties (but not the names) of about fifteen elements and asked to classify them into groups. Students were to state which properties were common to each group and also to order the elements within the group based on a property (i.e. going down from high density to low density).
Resources
Suggested Labs and Activities
1. Reactivity of Metals Lab Activity Flinn Scientific Lab Kit (Benchmark: 9C.2.1.1.2 Identify and compare trends on the periodic table, including reactivity and relative sizes of atoms and ions; use the trends to explain the properties of subgroups, including metals, non-metals, alkali metals, alkaline earth metals, halogens and noble gases.) (Benchmark: 9C.2.1.1.2 Identify and compare trends on the periodic table, including reactivity and relative sizes of atoms and ions; use the trends to explain the properties of subgroups, including metals, non-metals, alkali metals, alkaline earth metals, halogens and noble gases).
2. Electron configurations and the Periodic Table Atomic Structure and the Periodic Table (Benchmark: 9C.2.1.1.1 Explain the relationship of an element's position on the periodic table to its atomic number and electron configuration.)
3. There are also other Discovery Science videos related to the PeriodicTable Discovery Science Store In additionVideo # 7 "The Periodic Table" from the World of Chemistry video series would also be appropriate. World of Chemistry Handouts and lessons for the Discovery videos on the Periodic Table may be found at Discovery Science Lesson Plans or a handout of questions to accompany their viewing of the film.World of Chemistry Periodic Table Video Questions (Benchmark: 9C.2.1.1.2 Identify and compare trends on the periodic table, including reactivity and relative sizes of atoms and ions; use the trends to explain the properties of subgroups, including metals, non-metals, alkali metals, alkaline earth metals, halogens and noble gasses.)
4. Periodic Trends and The Properties of Elements Lab Flinn Scientific (Benchmark: 9C.2.1.1.2 Identify and compare trends on the periodic table, including reactivity and relative sizes of atoms and ions; use the trends to explain the properties of subgroups, including metals, non-metals, alkali metals, alkaline earth metals, halogen and noble gases.)
This lesson plan examines the properties of elements and the periodic table. Students learn the basic definition of an element and the 18 elements that build most of the matter in the universe. The periodic table is described as one method of organization for the elements. The concepts of physical and chemical properties are also reviewed.
Instructional suggestions/options
The Best Practices of Science Teaching
Many of the best practices are summarized and examples are given in the chapter "Guided inquiry in the science classroom" by Minstrell, J. & Kraus, P. found in How Students Learn: History, Mathematics, and Science in the Classroom. (M. Suzanne Donovan and John D. Bransford, Editors) Washington, DC: National Research Council (2005). Other best practices are to be found in Robert Marzano's Classroom Instruction that Works (2001) ASCD.
Here are three of the best practices for science teaching:
Regularly employ active learning strategies Classifying the properties of elements in groups using cards is an example of an active learning strategy.
Employ inquiry labs Flinn Guide to Periodic Table Labs and Demonstrations
Provide meaningful, engaged learning for all students such as the Reactivity of Metals lab.
Additional resources
1. "nClark" website which has links, resources and activities for the Periodic Table
Dozens of activities involving the Periodic Table
2. Comprehensive Interactive Periodic Table
3. Teachers Domain Lesson: The Shape of The Periodic Table This lesson explains why the elements exhibit periodicity, why the periodic table of elements is shaped the way it is, and how we are able to predict the characteristics of elements yet to be discovered or created.
4. SciLinks : Free web content to extend and expand student understanding
Reviewed and selected by experienced NSTA educators
Activities to bring science alive in the classroom
5. Periodic Table "Self Assessment"
Prentice Hall Chemistry
Kean, S. (2010). The disappearing spoon. New York, NY: Little, Brown and Company. The Disappearing Spoon: And Other True Tales of Madness, Love, and the History of the World from the Periodic Table of the Elements.
Vocabulary/Glossary
- Period - a horizontal row of elements in the Periodic Table
- Group (Family) -a vertical column of elements on the Periodic Table
- Alkali metal -Group I elements of the Periodic Table
- Alkaline earth metal -Group II elements of the Periodic Table.
- Halogens -Group VII elements of the Periodic Table
- Noble Gases -Group VIII elements of the Periodic Table
- Atomic Radius -the distance from the center of the nucleus of an atom to the edge of its electron cloud.
- Valence electrons -the electrons occupying the outermost s & p sub levels of the electron configuration of an element.
Assessment
Assessment of Students
Choose the letter of the correct answer that matches the statement for each question. Then explain your answer with one or two sentences. (Students are given a Periodic Table).
1. Which of the following lists has the atoms from smallest radius to largest radius?
A. B < C < N
B. Ar < Xe < Kr
C. Cl < S < S2-
D. Na < Na1+ < K
E. K1+ < Ca2+ < K
Answer: C (Cl < S < S2- ) Radii decrease going to the right within a period and so S > Cl. A negative ion is larger than the original atom because it has gained electrons and now the same number of protons are trying to hold more electrons. Bloom's taxonomic level: Application
2. The alkaline earth metals (Group II) in order of chemical reactivity would be
A. Be,Mg,Sr, Ra, Ba,Ca
B. Ra,Ba,Sr,Ca,Mg,Be
C. Be,Mg,Ca,Sr,Ba,Ra
D. Ca,Be,Mg,Ra,Sr,Ba
The answer is C (Be,Mg,Ca,Sr,Ba,Ra) because chemical reactivity increases for metallic groups down within the group since the atoms are more easily able to lose their outermost electrons. Taxonomic level: application.
3. The alkaline earth metals (Group II) in order of chemical reactivity would be
A. Be,Mg,Sr, Ra, Ba,Ca
B. Ra,Ba,Sr,Ca,Mg,Be
C. Be,Mg,Ca,Sr,Ba,Ra
D. Ca,Be,Mg,Ra,Sr,Ba
The answer is C (Be,Mg,Ca,Sr,Ba,Ra) because chemical reactivity increases for metallic groups down within the group since the atoms are more easily able to lose their outermost electrons. Taxonomic level: application
4. Which of the following atoms is least likely to form a positive ion?
A. fluorine
B. helium
C. lithium
D. silicon
E. cesium
The answer is E (cesium). Ionization energy decreases going left and down on the periodic table. The outermost electrons are further from the nucleus and easier to remove. Taxonomic level application
5. Compare and contrast the change in reactivity of the Group I metals going down the group with their change in atomic radii. Explain how the change in atomic radii relate to the metal's reactivity.
Answer: As one goes down Group I from Lithium metal to Cesium the atomic radii increase. Each period is adding an addition energy level. The one outermost valence electron becomes further and further from the pull of the protons in the nucleus. The energy needed to remove that electron to form a positive ion decreases. These metals become more reactive as they are able to lose their outermost electron more easily. Bloom's taxonomic level: Analysis
6. If one examines the Noble Gases they are found to be relatively nonreactive compared to the other elements in their period. Provide two reasons why this is true using the principals of electron structure.
Answer: the noble gas elements are the smallest atoms in their period. Their outermost electrons would be closest to the nucleus and require more energy to remove. More importantly, the noble gas atoms have filled outer levels (such as Helium which has a filled second level). All noble gases except Helium have eight electrons in their outer level. This is a "stable" electron arrangement and more energy is required to remove the valence electrons. Taxonomic level: Comprehension and Analysis
Assessment of Teachers
1. Explain the main difference(s) between the way Mendeleev organized his elements on the Periodic Table and the way they are organized on the current Periodic Table.
Answer: Mendeleev placed the known elements in his time by order of increasing atomic mass and then grouped them together in vertical columns by similar physical and chemical properties such as the formula of the element with oxygen. He found that he had to have "gaps" in the elements so that this arrangement could be maintained . He had fewer elements in his table and the entire column of Noble Gases was missing because only Helium had been discovered.
The modern periodic table places the elements in order of increasing atomic number, that is the number of protons n the nucleus of the atom. The number of protons also corresponds to the number of electrons in the atom. It is the electrons and their arrangement which determines the chemical properties of an element.
2. How might you assist students in understanding how electron configurations help explain why elements in a group have similar chemical and physical properties?
Students must have a clear understanding of the electron configuration of the valence electrons of an atom in order to understand how the elements in groups have similar chemical and physical properties. Have students examine the electron configurations of elements and learn to recognize the number of valence electrons and their arrangement. Then look for patterns among groups of elements. For example all elements in Group I have an electron configuration which ends in s1. Note the relationship between the energy level of the s orbital and the period of the element. Have students identify "regions" of the Periodic Table which represent the filling of specific orbitals and sub levels.
3. How does an elements position on the Periodic Table relate to its chemical reactivity?
Help students recognize the two main classification of elements, metals and nonmetals. Examine the general location of metals and nonmetals. What is generally true about the electron configuration of elements that are metals? What about nonmetals? When forming ions and reacting how do metals behave? How do nonmetals behave? Which metal would be the most reactive? Which nonmetal? What is the connection between the position of an element on the Periodic Table and its reactivity?
Differentiation
Struggling and At-Risk
Struggling and At-Risk learners often have difficulty maintaining regular attendance. Encourage the student's desire to be in school by planning activities that engage the student (see Best Practices above).
The Sourcebook for Teaching Science - Strategies, Activities, and Instructional Resources
The science classroom is often a frustrating place for English language learners. Science has a complex vocabulary that is difficult even for native English speakers to learn. Difficulty learning English should not be confused with an inability to think scientifically. Many of the strategies that are useful for English language learners are effective for differentiating instruction for others.
A very good resource for SpEd students in the science classroom. Also ELL.
Teaching Today | How-To Articles | Supporting Special Education Students in Science
For students with ADHD concepts should be broken into smaller chunks.
Parents/Admin
Administrators
Administrators should observe students actively engaged in the learning process. Students may be involved in lab activities which illustrate the concepts being studied. Students might be engaged in small group work to analyze information and make predictions. Examples would be students working together to organize cards with the properties of elements into a periodic table or working together to graph periodic properties and make predictions.
Parents can help their student understand the basis for the Periodic Table by having their child classify and group objects around the house. How could the items in a kitchen drawer for example be put into groups (using size, shape, color, function etc.)? Older children could create a "periodic table collage" with a theme using pictures from a catalog or magazine. For example one could make a "Periodic Table of Sports Equipment" with pictures of various types of sporting goods equipment such as shoes, balls, gloves, protective wear, etc. The student could organize the items within groups by a propert such as size (small balls down to larger), expense or function.
Teachers, this also makes an excellent activity to use at the start of the unit to engage the students and explore the process skills of sorting and classification.