WHAT IS IT THAT YOU CAN

PUT INTO A BARREL TO MAKE THE

BARREL LIGHTER?

Students, and sometimes teachers do not think outside the box in

order to come up with a solution to a problem

PERIODIC TRENDS

CONCEPT PRESENTATIONHow do you make the invisible,

visible?

By: Nickolaos Tsigaridis

Mentor: Amy Yu

“It is owing to wonder that people begin to philosophize and thus wonder remains the beginning of knowledge”

Aristotle 250 B.C.

BACKGROUND INFORMATION How can a teacher teach something that

they themselves has never seen?

This is the task that teacher’s must overcome during the chemistry unit in grade 9 and then again in the grade 11 university chemistry course

“Men should strive to think much and know little.”

Democritus 450 B.C.

BACKGROUND INFORMATION CONTINUED To elucidate this, teachers must use the

tools that are present to them even those that they may not think to use

CURRICULUM EXPECTATIONS

The concept of periodic trends is found in two courses in the curriculum expectations

The grade 9 course holds the fundamental information for success in the grade 11 course

SNC1DSNC1D

SCH3USCH3U

Demonstrate an understanding of the properties of common elements and compounds, and of the organization of elements in the periodic table.

Demonstrate an understanding of the properties of common elements and compounds, and of the organization of elements in the periodic table.

Demonstrate an understanding of periodic trends in the periodic table and how elements combine to form chemical bonds.Demonstrate an understanding of periodic trends in the periodic table

and how elements combine to form chemical bonds.

SPECIFIC EXPECTATIONS GRADE 9

Course Unit Expectation Code

Expectation

SNC1D Chemistry C2.1 use appropriate terminology related to atoms, elements, and compounds, including, but not limited to: boiling point, mixtures, particle theory,pure substances, and viscosity

C3.1 explain how different atomic models evolved as a result of experimental evidence (e.g., how the Thomson model of the atom changed as a result of the Rutherford gold-foil experiment)

C3.2 describe the characteristics of neutrons, protons, and electrons, including charge, location, and relative mass

C3.5 describe patterns in the arrangements of electrons in the first 20 elements of the periodic table, using the Bohr‑Rutherford model

C3.6 explain the relationship between the atomic structure of an element and the position of that element in the periodic table

SPECIFIC EXPECTATIONS GRADE 11

Course Unit Expectation Code

Expectation

SCH3U Matter, Chemical trends, and chemical bonding

B2.1 use appropriate terminology related to chemical trends and chemical bonding, including, but not limited to: atomic radius, effective nuclear charge, electronegativity, ionization energy, and electron affinity

B2.2 analyze data related to the properties of elements within a period (e.g., ionization energy, atomic radius) to identify general trends in the periodic table

B3.1 explain the relationship between the atomic number and the mass number of an element, and the difference between isotopes and radioisotopes of an element

B3.2 explain the relationship between isotopic abundance of an element’s isotopes and the relative atomic mass of the element

B3.3 state the periodic law, and explain how patterns in the electron arrangement and forces in atoms result in periodic trends (e.g., in atomic radius, ionization energy, electron affinity, electronegativity) in the periodic table

MISCONCEPTIONS There are three misconceptions that I

will focus on for this presentation and related to this topic1. Chemistry is too difficult to understand,

especially the periodic table

2.The atom is so small and I can not see it, how do I really know what it looks like

3. There are so many periodic trends, how can I remember them all?

MISCONCEPTION 1

Chemistry is too difficult

to understand especially,

the periodic table“True knowledge is knowing that you know nothing”

Aristotle 250 B.C.

MISCONCEPTION 1 - EXPLAINED

Students find themselves to be overwhelmed with the huge amount of information

Learning to use the periodic table properly will alleviate much of the stress

Building knowledge of how to use the table early in high school will allow the student to excel when it comes to learning more difficult concepts

“Give a man a fish, he eats for a day, teach a man to fish, he eats for a lifetime”

MISCONCEPTION 1 - STRATEGIES Literacy – Using a word wall or

“Greek/Latin” page can help the students learn many of the root words which will help them remember the stories behind the elements

Visual Aid – Using the structure of the periodic table to determine how to use it rather than strict rote memory

Analogies – using the analogy of siblings you are able to determine simple relationships amongst elements

“Vision without action is just daydreaming”

MISCONCEPTION 1 - STRATEGIES Labs/Demo – there is probably nothing

more important and beneficial for a student than a hands on activity where they get to use the actual elements they are learning about. The students will use the spectrum that is created from vaporizing elements in order to determine their place in the periodic table

Videos - The series “Discovering the Elements” can give the students a unique look at elements that are not present in schools

Activity

MISCONCEPTION 2

The atom is so small and I

cannot see it, how do I

really know what it looks

like?

A scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die and a new generation grows up that is familiar with it.

Max Planck

MISCONCEPTION 2 - EXPLAINED

The road to understanding the structure of the atom has its roots deeply embedded in the pages of history.

It is through this history that the true structure of the atom can come to life.

Using history and relating it to a student’s modern day experience can help the student discover the elusive structure of an atom.

“Even when laws have been written down, they ought not always to remain unaltered.”

Aristotle 250 B.C.

MISCONCEPTION 2 - STRATEGIES Story telling – The history of science gives us

a unique way as a teacher to use modern day soap operas to model how the structure of the atom was discussed, making this a fun lesson will help the students (get some pop corn and set up a theatre and put on a show). Remember, scandals are really easy to remember.

Prior Knowledge – Using the previous lessons on discovering the elements and the periodic table students will be able to use that knowledge to begin to build their own atoms based on the information gathered from the correct use of the periodic table

“The person that asks a question is a fool for five minutes, the person who does not, is still a fool”

MISCONCEPTION 3

There are so manyperiodic trends and it’s so

hard to remember all their

explanations, how do I do

it?

“Facts are the air of scientists. Without them you can never fly.”

Linus Pauling

MISCONCEPTION 3 - EXPLAINED

At this point you have uncovered the structure of the atom

where that structure has come from, and

how to properly use the periodic table.

With that information, usually the students will be able to come up with conclusions on their own about the different periodic trends.

MISCONCEPTION 3 - STRATEGIES Analogies – Using meaningful analogies that

are easy to remember will help the students understand the periodic trends

Demos/Videos – using and reusing the same demos/videos to help the students understand different concepts helps solidify the periodic trend that you are trying to explain and also indirectly re-supporting prior knowledge learned in the course or in completely different courses.

Kinaesthetic – Getting the class up and moving keeps the students motivated and very sharp. Making them take part in the lessons helps them retain the information.

Activity

LESSON SEQUENCE Day 1 – Formative Assessment – A

demonstration of the reaction of sodium and potassium in water will be performed and the students will be asked to remember what happens in detail.

Students will be introduced to the periodic table including deducing how to use the periodic table to withdraw pertinent information and why the structure of the periodic table is important to that information gathering.

The students will also watch selected segments of a video “Discovering the elements” as they have access to elements that the students will usually not have access to (ex., Mercury).

LESSON SEQUENCE Day 2 – Summative Assessment – The

students will take part in a lab called the “flame test” lab

Different salts are placed on a deflagrating spoon and placed in the flame of the Bunsen burner.

The flame will cause the different elements produce different colours of light.

It is the student’s job to take the information gathered during the lab and relate it to the position that elements are represented in the periodic table

LESSON SEQUENCE Day 3 – Formative Assessment –

Students will be exposed to the history of science through a story telling session in order to understand how the history of the development of the atom is important to understand why the structure of the atom is the way it is.

LESSON SEQUENCE Day 4 – Formative Assessment –

Recalling the demonstration from the first day, students are asked to now determine what is happening at an atomic level to the atoms.

Explanations of common periodic trends (ex., atomic radius, electronegativity, electron affinity, and ionization energy) can be related to that original demonstration.

LEARNING STYLES The lessons outlined throughout this

presentation offer a unique opportunity to interact with all the different types of learnersKinaesthetic learners have the opportunity

to get up and try activitiesAuditory Learners have the ability to listen

and ask questions, much in the way the early philosophers did

Visual learners have the chance to watch demonstrations and see, visually, analogies on the board or screen of difficult concepts made easy

SAFETY CONSIDERATIONS

As in any science chemistry has many safety considerations

We must remember that the students will be coming into contact, or in the near vicinity of dangerous chemicals, whether they are dangerously reactive, toxic, poisonous, or teratogenic to name a few, we must take precautions when performing the labs and demos

“In all science, error precedes the truth, and it is better it should go first than last”

Hugh Walpole

SAFETY CONSIDERATIONS CONTINUED

Example – Na and K with water usually react violently but are typically

harmless to students Explosions can occur uncontrollably and can

cause glass and chemicals to fly outwards injuring students

Disposal – Sometimes the dangers of labs and demos do not end with the lab or demo themselves Example – Na and K with water disposal

Garbage fires are common if there is un-reacted Na or K present

SOCIETAL IMPLICATION the fact that everything in the visible

universe is made of atoms and knowing general information of how they work may prove to be invaluable

Learning how to use the periodic table is in order to divulge more information about the elements is analogous to learning how to use a map in order to determine the location of the school in which you sit.

Bad times have a scientific value. These are occasions a good learner would not miss.

Ralph Waldo Emerson

REFERENCES 1. Ontario Curriculum, Science and Technology, Grades 11

and 12, revised 2008. Presented in the document are the curriculum expectations that were used to create the unit plan

 2. Nakhleh MB. 1992. Why some students don’t learn chemistry:

Chemistry Misconceptions. Journal of Chemical Education. 69.3. p191The article discusses student’s misconceptions about chemistry

 3. Özmen H. 2004. Some Student Misconceptions in Chemistry:

A Literature Review of Chemical Bonding. Journal of Science Education and Technology. 13. 2. P147-159This is a literature review that looks at several articles and summarizes some of the misconceptions in chemistry that students have