Atoms and Molecules

Lesson Plan of Introduction to Atoms and Molecules

General Science Grade VI

Students’ Learning Outcomes

· Different between an atom and a molecule.

· Recognize the symbols of some common elements.

· Differentiate between elements, compounds and mixtures.

· Identify examples of some compounds and mixtures from their surroundings.

Information for Teachers

Concept Map

· Matter is anything that takes up space and has mass.

· All matter is made of atoms.

· Atoms are the building blocks of matter. Kinds of how bricks of the building blocks of the houses.

· Atom: The basic unit of a chemical element.

· Atom: An extremely small amount of a thing or quality.

· Atoms are composed of particles called protons, electrons and neutrons

· An element is a pure chemical substance which contains same type of atoms.

· A molecule is the smallest particle in a chemical element or compound that has the chemical properties of that element or compound. Molecules are made up of atom s that are held together by chemical bonds. These bonds form as a result of the sharing or exchange of electron s among atoms

· A symbol is a letter used to represent something.

· Chemists use symbols to represent elements. Chemists use one or two letters to represent elements.

· The symbol for aluminum is Al.

· The symbol for oxygen is O.

· A compound is a substance formed when two or more elements are chemically joined.

· Water, salt, and sugar are examples of compounds.

· When the elements are joined, the atoms lose their individual properties and have different properties from the elements they are composed of.

· A chemical formula is used as a quick way to show the composition of compounds.

· Molecules of element have same kind of atoms while molecules of compound have different kind of atoms.

· A mixture is made up of two or more different substances which are mixed together but are not chemically combined.

Material / Resources

Paper clips (12 of each color i.e. green, red and yellow), sulfur powder, iron fillings, china dish, burner/spirit lamp, bar magnet

Worm up activity

· Write the word “Atom” on board and ask students to tell what they know about an “Atom”

· Write their answer on board and give a brief touch to each answer.

Introductory Activity

· Draw equal sized small circles as shown below in the box- a on board.

· Draw circles larger in size than those of box- A as shown in the box – B on board.

· Each circle represents an atom.

· Ask students to observe/see the circles and answer the following questions.

o Can we represent atoms by small circles?

o Are these circles of the same size of both boxes?

(Tell the students that atoms of the same size and shape form a pure substance known as an element).

o Can circles of both the boxes A & B represent atoms of the same element?

o Define an element in your own words.

Development

Activity 1

· Divide students in groups; provide different colored paper clips to each group and say:

· A green paper chip represents a hydrogen atom (symbol H).

· A red paper clip represents an oxygen atom (symbol O).

· A blue paper clip represents a carbon atom 9symbol C).

· Ask students to hold one red paper clip in each hand and again ask. Can you consider it an atom?

· instruct students to:

o Combine two red paper clips and show it to the teacher. (Ask: what is it? is this an atom or something else?)

o Introduce the term “molecule”. Tell students that atoms combine to form a molecule. When two oxygen atoms combine they form an oxygen molecule.

o Ask: can different atoms form a molecule? (Yes/No)

o Yes, write the formula of H2O (water) on board and ask groups to name atoms present in H2O.

o Students to attach two green paper clips with one red paper clip. This is the model of H2O.

o Ask students to form the structure / model of CO2 (Carbon dioxide) by using paper clips of respective colors. (2 red paper clips with one yellow paper clip). Give feedback if required.

Activity 2

· Introduce “mixture” and write its definition on board. “When two or more than two substances are mixed in such a way that no new substance is formed”.

Step 1:

Divide students in groups and instruct them to:

o Take some sulfur crystals in a china dish.

o Mix them with some iron filings.

o Observe the mixture whether its constituents have lost their original properties or not.

o Move a bar magnet in the mixture.

o Observe what happens.

o Show the result to the teacher.

· Ask how is it a mixture? (Explain it is a mixture because iron and sulfur can be

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· Step 2:

Divide students in groups. Give them material and instruct them to:

o Mix iron filings with sulfur crystals in a china dish.

o Heat the mixture strongly.

o Observe what happens with iron and sulfur.

o Let the matter cool to room temperature.

o Move a bar magnet in the substance present in china dish.

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Conclude the activity by asking:

· Q1:Why don’t iron filings separate from the substance formed on heating the mixture?

(Expected response: Due to heating, the iron filings reacted with sulfur chemically and formed a new compound)

· Q2: What type of substance is formed on heating the mixture of sulfur and iron?

(Expected response: Iron sulphide)

· Q3: give examples of some common compounds and mixtures.

(Expected response: Compounds: water, common salt, Mixture: Air, steel, ice cream)

Sum up / Conclusion

Explain children that we learn:

· The smallest particle of an element is atom.

· Atoms of different elements have different sizes and combine to form compounds.

· Atoms can’t exist independently except that of noble gases.

· Components of mixtures can be separated by physical methods.

· Molecules of element have same kind of atoms while molecules of compound have different kind of atoms.

Assessment

Ask:

· What is an atom?

· What is the difference between an atom and a molecule?

· What is H, C, O?

· Tell them that atoms/elements are recognized by “symbols” which is the shortest name of an element. Show students a periodic table and have a brief discussion on the symbols of the following like He, Na, N, Ca, fe elements.

Follow up

· Make the following models with the help of the colored paper clips.

· List down 4-4 examples of mixtures & compounds occurring/present in our surroundings.