Chemical Properties

Physical Science

The structure of the atom determines chemical properties of elements.

Benchmark: Particles in Atoms

Describe the relative charges, masses, and locations of the protons, neutrons, and electrons in an atom of an element.

Benchmark: Models of the Atom

Describe how experimental evidence led Dalton, Rutherford, Thompson, Chadwick and Bohr to develop increasingly accurate models of the atom.

Benchmark: Periodic Table

Explain the arrangement of the elements on the Periodic Table, including the relationships among elements in a given column or row.

Benchmark: Isotopes

Explain that isotopes of an element have different numbers of neutrons and that some are unstable and emit particles and/or radiation.

For example: Some rock formations and building materials emit radioactive radon gas.

Another example: The predictable rate of decay of radioactive isotopes makes it possible to estimate the age of some materials, and makes them useful in some medical procedures.


Standard in Lay Terms 

MN Standard in Lay Terms

The chemical properties of all elements are the result of differences in atomic structure.

Big Ideas and Essential Understandings 

Big Idea

Atoms are arranged in rows and columns in the periodic table depending on the number of protons.  Along with protons, atoms also have electrons and neutrons.  An element that has the same number of protons but a different number of neutrons is called an isotope and some of these are extremely unstable making them radioactive.  All of this information was discovered over the last 150 years by chemists.  The people given credit for the development and modification of these models include, Dalton, Thompson, Rutherford, Chadwick and Bohr.

Benchmark Cluster 

MN Standard Benchmarks

Describe the relative charges, masses, and locations of the protons, neutrons, and electrons in an atom of an element.

Describe how experimental evidence led Dalton, Rutherford, Thompson, Chadwick and Bohr to develop increasingly accurate models of the atom.

Explain the arrangement of the elements on the Periodic Table, including the relationships among elements in a given column or row.

Explain that isotopes of an element have different numbers of neutrons and that some are unstable and emit particles and/or radiation.

The Essentials


Structure of atoms

12BPS1.1 Matter is made of minute particles called atoms, and atoms are composed of even smaller components. These components have measurable properties, such as mass and electrical charge. Each atom has a positively charged nucleus surrounded by negatively charged electrons. The electric force between the nucleus and electrons holds the atoms together.

12BPS1.2 The atom's nucleus is composed of protons and neutrons, which are much more massive than electrons. When an element has atoms that differ in the number of neutrons, these atoms are called different isotopes of the element.

Historical perspectives

12GHNS3.1 In history, diverse cultures have contributed scientific knowledge and technologic inventions. Modern science began to evolve rapidly in Europe several hundred years ago. During the past two centuries, it has contributed significantly to the industrialization of Western and non-Western cultures. However, other non-European cultures have developed scientific ideas and solved human problems through technology.

12GHNS3.2 Usually, changes in science occur as small modifications in existing knowledge. The daily work of science and engineering results in incremental advances in our understanding of the world and our ability to meet human needs and aspirations. Much can be learned about the internal workings of science and the nature of science from study of individual scientists, their daily work, and their efforts to advance scientific knowledge in their area of study.

12GHNS3.3 Occasionally, there are advances in science and technology that have important and long lasting effects on science and society. Examples of such advances include the following: Copernican revolution, Newtonian mechanics, Relativity, Geologic time scale, Plate tectonics, Atomic theory, Nuclear physics, Biological evolution, Germ theory, Industrial revolution, Molecular biology, Information and communication, Quantum theory, Galactic universe, Medical and health technology.

12GHNS3.4 The historical perspective of scientific explanations demonstrates how scientific knowledge changes by evolving over time, almost always building on earlier knowledge.

The Physical Setting - Atoms and Molecules -

Historical Perspectives - The Chemical Revolution - Green Volume 2: page 80-81

This map links scientific understanding to the history of the development of atoms and elements which in turn leads to the nature of science and ideas changing over time.

Historical Perspectives - Splitting the Atom - Green Volume 2: page 82-83

Benchmarks of Science Literacy

Physical Setting - D. The Structure of Matter

Atoms are made of a positively charged nucleus surrounded by negatively charged electrons. The nucleus is a tiny fraction of the volume of an atom but makes up almost all of its mass. The nucleus is composed of protons and neutrons which have roughly the same mass but differ in that protons are positively charged while neutrons have no electric charge. 4D/H1*

Although neutrons have little effect on how an atom interacts with other atoms, the number of neutrons does affect the mass and stability of the nucleus. Isotopes of the same element have the same number of protons (and therefore of electrons) but differ in the number of neutrons. 4D/H3*

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/H6

Historical Perspective - F. Understanding Fire

In the late 1700s and early 1800s, the idea of atoms reemerged in response to questions about the structure of matter, the nature of fire, and the basis of chemical phenomena. 10F/H1**

Lavoisier pioneered a new approach to chemistry based on the modern definition of an element and quantitative methods. His system for naming substances and describing their reactions in terms of the elements that make them up contributed to the rapid growth of chemistry by enabling scientists everywhere to share their findings about chemical reactions without ambiguity. 10F/H2*

In the early 1800s, British chemist and physicist John Dalton united the concepts of atoms and elements. He proposed two ideas that laid the groundwork for modern chemistry: first, that elements are formed from small, indivisible particles called atoms, which are identical for a given element but different from any other element; and second, that chemical compounds are formed from atoms by combining a definite number of each type of atom to form one molecule of the compound. 10F/H3*

Dalton figured out how the relative weights of the atoms could be determined experimentally. His idea that every substance had a unique atomic composition provided an explanation for why substances were made up of elements in specific proportions. 10F/H4**

Since Lavoisier and Dalton, the system for describing chemical reactions has been vastly extended to account for the configuration taken by atoms when they bond to one another and to describe the inner workings of atoms that account for why they bond as they do. 10F/H5*

Historical Perspectives - G. Splitting the Atom

Common Core Standards                  

2010 Literacy Standards - Reading Benchmarks: Literacy in Science and Technical Subjects 6-12


Student Misconceptions 

From NSDL Science Literacy Maps

Students of all ages

lack appreciation of the very small particles

believe there must be something in the space between particles

have difficulty appreciating the intrinsic motion of particle in different states

have problems conceptualizing forces between particles.


Ms. F has her students get into pairs and hands five shiny new pennies to each pair. Together, the students complete the formative assessment probe "Pennies" (Uncovering Student Ideas in Science - Volume 4). She has each pair find another to discuss how they determined what are properties of the penny and what are properties of the atoms that make up the penny. She wanders the room as students talk so she can hear what the kids are thinking about atomic properties. This gives her an idea of where to begin her lesson and what to include.

Knowing that students have covered the basic parts of an atom in middle school, she takes more time to describe in detail these parts and who discovered them. Knowing that just telling the kids about the information can make it far less interesting, Ms. F leads in with her homemade children's book "A Story of the Atom". This is a storybook of the "characters" (scientists) that experience a special "ball" (atom) they find while wandering through the woods. When she finishes, she assigns an internet scavenger hunt that contains the basic history of how the atomic theory came to be and where it is currently going. She is careful to choose mostly middle school sites so that the readability of the information is at the level of all of her students. Within each section of the webquest, each student is required to go to the class Moodle site and take a 10 question quiz (they must repeat this quiz as many times as necessary to get all the questions correct). This helps Ms. F monitor progress and be sure that the most relevant and required parts of the lesson are completed and understood. When using computer time, it is common for students to waste time wandering through websites, daily essential learnings are necessary to keep them on task with goals in mind.

On the last day of the week, Ms. F has the students individually complete another formative assessment called "Iron Bar". She has adjusted it to pose the same type of questions about the pennies to determine if students now understand how the atoms behave individually as well as a group sot that the iron has specific properties. (This acitivity will be discussed again later in the course when Ms. F talks about energy and how the particulate nature of matter determines how and why energy is transferred between objects.)

The following Monday, Ms. F introduces a classification investigation to introduce how atoms are arranged on the periodic table. She uses the Alien Period Table Activity where students study stick figures and group them into a table format. This is the beginning of the next part of her unit about the periodic table and how elements are arranged by properties. Some students struggle at the start of the activity, but as Ms. F circulates around the room addressing some questions with her own questions, students get the hang of it. When students feel they have "completed" the table, Ms. F has them do a gallery walk, noting other students' tables and how they are similar and how they are different, but that all are categorized into rows and columns. She has the students write a summary of what properties they used for each row and column making sure they had multiple reasons for each.

Once students understand classification by appearance, Ms. F has them look at a periodic table of elements for the first 45 elements. The students are given a homework assignment asking specific questions about each element as well as instructions on how to color particular elements. When completed, Ms. F can see if the students understand how to read the information by looking at the finished, colored table. The next day, she helps them prepare a prelab for the investigation they will do for the next two days about common elements in the environment where students will record observations about the physical and chemical behavior of selected elements. At the end of several weeks, students are given a final assessment including several questions from the formative assessment students completed earlier.

Another helpful vignette to read can be found in Michaels, S, Shouse, A, & Schweingruber, H. (2008). Ready, set, science! putting reseacr to work in k-8 science classrooms. Washington, D.C.: The National Academies Press.   pg 45-57  


Instructional Notes 

Suggested Labs and Activities

Alien periodic table activity - using stick figures, students organize characters in rows and columns according to their similar properties(several versions are available online)

World of Chemistry Videos - basic information in 25 minute videos done by the Annenberg foundation

Episode 6:  The Atom - Viewers journey inside the atom to appreciate its architectural beauty and grasp how atomic structure determines chemical behavior.

Episode 7:  Periodic Table - The development and arrangement of the periodic table of elements is examined.

Element Facebook page - Have students create a facebook page of an element - you can create your own template if necessary (create a template, or profile publisher)

Scientist Facebook page - Possible template for a person

Have students take a quiz on "What Element Am I?"

Instructional suggestions/options

Teachers can collaborate closely with colleagues in grades 6-8 to ensure a progression of learning in the sub-strand matter.  A close alignment of 6-8 curriculum will best prepare students for more advanced work in chemistry.

As the teacher prepares to teach this standard pay close attention to  the national documents (NSES and Benchmarks) for deeper understanding of the intent of the standard.

This standard if very broad and should be "chunked" during instruction with several smaller assessments given throughout the learning process.

Instructional Resources 

Additional resources

Nancy Clark's Atom website - various activities for all levels of learning

Nancy Clark's Periodic Table website

Mrs. J's Physical Science website - beginning material in chemistry for ninth graders

Chem4Kids - If you are looking for basic chemistry information, stay on this site. It's not just for kids, it's for everyone. We have information on matter, atoms, elements, the periodic table, reactions, and biochemistry. If you're still not sure what to click, try our site map that lists all of the topics on the site. If you surf and get lost in all of the information, use the search function on the side of the pages.

New Vocabulary 


John Dalton:  Credited with the first theory that described what atoms are and how they behave:

Dalton's Atomic Theory (1807-08):

  • all matter is made of atoms
  • atoms of the same element are identical
  • atoms of different elements are different
  • atoms are indivisible, and are not created or destroyed in chemical reactions.

J.J. Thomson:  (1897) discovered the electron.  This discovery was important because it was the first evidence that atoms were divisible. 

"plum pudding" model:  (1904) The "pudding" was the positively charged substance that most of the atom was made of, and the "raisins" were the negatively-charged electrons.

Ernest Rutherford:  (1909) discovered the nucleus. 

Neils Bohr:  (1913) applied math to Rutherford's planetary model of the atom.  The energy of each electron determined its distance from the nucleus. 

Sir James Chadwick:  (1932) discovered the neutron

atom:  the smallest piece of an element that retains the properties of that element.

nucleus:  a dense region in the center of an atom.  The nucleus is made of protons and neutrons, and contains almost all of an atom's mass.

proton:  a subatomic particle found in the nucleus of an atom.  It has a charge of +1, and a mass of approximately 1 atomic mass unit (amu).

neutron:  a subatomic particle found in the nucleus of an atom.  It has no charge (is neutral), and has a mass of approximately 1 amu.

electron:  a subatomic particle found outside the nucleus of an atom.  It has charge of -1 and a mass of approximately 1/2000 amu.  Atoms can gain, lose, or share electrons in chemical reactions.

atomic number:  the identity of an atom is based on the amount of (positive) charge in its nucleus.  (This works because particles from the nucleus cannot be given to or shared with another atom.)  The atomic number is the number of protons in the nucleus.  Each element has a unique atomic number.

isotopes:  atoms of the same element (same atomic number = same # of protons), but that have different numbers of neutrons (and therefore different mass numbers) from each other.

Isotopes are described by their mass numbers.  For example, carbon-12 (12C) has 6 protons and 6 neutrons, which gives it a mass number of 12.  Carbon-14 (14C) has 6 protons and 8 neutrons, which gives it a mass number of 14.

element symbol:  a one- or two-letter abbreviation for an element.  (New elements are given temporary three-letter symbols.)  The first letter in an element symbol is always capitalized.  Other letters in an element symbol are always lower case. 

periodic table of the elements:  a table listing all of the known chemical elements.  Elements are arranged in order by increasing atomic number (number of protons). The rows and columns of the periodic table are arranged such that elements in the same column have similar arrangements of their electrons, and therefore similar chemical and physical properties.

Technology Connections 

PhET Simulations

Build an Atom - Use the number of protons, neutrons, and electrons to draw a model of the atom, identify the element, and determine the mass and charge.

Models of the Hydrogen Atom - Explain why people believed in each model and why each historical model was inadequate.  (also Benchmark   -   Analyze the strengths and limitations of physical, conceptual, mathematical and computer models used by scientists and engineers.)


Assessment of Students

Which statement about matter is TRUE?

1.    Atoms are not matter but they are contained in matter.

2.    Matter exists only when you can see it.

3.    Living things are not matter.

4.    Matter is made up of atoms.

Imagine that you remove all the atoms from a chair. What remains?

1.    Nothing

2.    A pile of dust

3.    The same chair

4.    A chair that weighs less

Write a brief summary of the basic models used during the development of the atomic theory.

Assessment of Teachers

a.    A student says "Well, why don't I fall through my chair if an atom is mostly empty space?" How would you address the question?

b.    How can you use everyday materials and build a model with your kids to help them understand the abstract idea of the modern atom without supporting the misconception that an atom is set up like a solar system?


English Language Learners 

Teaching Science to ELL - part 1 and 2 - NSTA journal The Science Teacher  articles available for free on ELL language and learning.

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.

Teaching Science to English Language Learners: Building on Students' Strengths - Can a student's cultural background support learning in science? Or is concentrating on the specialized vocabulary of science the best way to help English language learners learn science? This book addresses these and other pressing questions you face when working with students whose linguistic and cultural backgrounds, as well as their languages, are different from your own.

Extending the Learning 

Pre-AP Strategies is set up for higher level of thinking skills


The Myth of the Culture of Poverty - Paul Gorski

EdChange - Resource site for Diversity, Multiculturalism and Cultural Competence

Special Education 

Supporting SpEd in Science Classrooms (article)

Anytime lessons and activities can be posted online ahead of time or shortly after help those students who struggle with notetaking and organization.

Short quizzes often rather than one exam is necessary for limited processing students.

Cornell Notes

word walls can be a good way to reiterate vocabulary


Classroom Observation 

Students should be engaged in building atomic models, creating element paintings, or using simulations to make this abstract idea more tangible.