LESSON 2- WHAT ARE ELEMENTS?
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AIMS:
1. What are elements?
2. What are properties of elements?
3. What is the Periodic Table of Elements?
4 What are compounds, suspensions, and mixtures?
MOTIVATION:
Read or pass out copies of the following poem, taken from Fizz, Bubble, and Flash, by Anita Brandolini. Discuss its meaning.
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A Periodic Poem Each element has a spot on the Periodic Table, Whether metal or gas, radioactive or stable. You can find out its number, its symbol, its weight, And from its position, its physical state. Elements lined up in columns and rows, The reason for this order, as each chemist knows, Is that atoms are made up of still smaller bits, (Figuring this out tested scientists' wits!). In the nucleus, protons and neutrons are found, And a cloud of electrons is buzzing around. First take one proton, put in its place; Now you have hydrogen, the simplest case. Add two neutrons and one more proton, And suddenly the hydrogen's gone! Now you have helium, quite different stuff... You get the picture; I've said enough, These tiny particles: they're like building blocks That make people and buildings, flowers and rocks. They create all of the elements we find, In everyday things of every kind! |
Show children pictures of the following elements:
1. gold 2. silver 3. sulfur 4. hydrogen flame 5. mercury 6. copper
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Ask questions that will lead children in describing the properties of each element.
Examples:
1. What is the color?
2. What is the state?
3. What is the texture?
PROCEDURE:
1. Have students log onto the following websites to fill in the database on terms dealing with elements: http://chem4kids.com/files/elem_intro.html and http://schoolscience.co.uk/content/3/chemistry/materials/match4pg1.html For a blank student database, click here.
| TERM | DEFINITION |
| Element | An element is a pure substance which cannot be split up by a chemical reaction. |
| Compound | A substance like water, that is made up of two or more elements, is called a compound. |
| Mixture | Mixtures are usually how you find things in nature. Rocks, the ocean, just about anything you find. They are substances held together by PHYSICAL FORCES, not chemical. |
| Periodic Table of Elements | As you probably saw, the periodic table is organized like a big grid. The ELEMENTS are placed in specific places because of the way they look and act. If you have ever looked at a grid, you know that there are ROWS (left to right) and COLUMNS (up and down). The periodic table has rows and columns too and they each mean something different. |
| Solution | Solutions are groups of molecules that are mixed up in a completely even distribution. |
| Suspension | A suspension is different from a solution. The solid particles have not dissolved but are suspended in the liquid. Suspended literally means that they are being held up or supported. |
| Solute | A solute is the substance to be dissolved. |
| Solvent | The solvent is the one doing the dissolving. |
| Dissolve | A solid dissolves in a liquid when it mixes completely with the liquid. The solid has broken down into pieces so small that its particles spread all through the new mixture. The solid and liquid will stay mixed without shaking. |
2. Students can do a variety of activities on line. Have them go to the following sites and do:
a. At this site students can do a Yahooligans Element Lab. It goes from naming the elements to more complex chemical combinations. http://yahooligans.yahoo.com/games_popup.php?g=fcs_ds1,b&50&70
b. Element Match Game- The games keep changing. Lots of fun! http://quia.com/mc/323341.html
c. Have students go to http://schoolscience.co.uk/content/3/chemistry/materials/match4pg1.html and take the quiz. They will be asked to tell whether the substance is a compound or mixture.
3. Introduce the Periodic Table of Elements: The following Table was taken from http://chemicalelements.com/
![[Periodic Table of the Elements]](http://chemicalelements.com/graphics/table.gif)
For children in grades 3-5 it is not necessary to delve into details of the Periodic Table. They should know that it a way to organize the elements according to similar properties. You may want to discuss metals and nonmetals as two of the groups. Children should become familiar with the chemical notations for the elements. Some activities to do on the Periodic Table can be found at:
a. http://1001-periodic-table-quiz-questions.com/ At this site, children can take a Periodic Table Quiz.
b. http://chemicalelements.com/ The site where this Table was taken from can be clicked on. Have students identify at least 5 elements and find its Atomic number, name, and properties.
ACTIVITIES:
The following activity is taken from Chemistry for Every Kid by Janice Van Cleave, John Wiley and Sons, Inc.
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Streamers of Color Problem: How can we observe the dissolving of a solute in a solvent? Hypothesis: If a substance is soluble in water, then we can show it dissolving, Materials: Clear drinking glass, powdered fruit drink, flat toothpick Procedure: 1. Fill the glass with water. 2. Select a dark colored powdered fruit drink. 3. Use the wide end of a flat toothpick to pick up a scoop of the powdered drink. 4. Gently shake the powder over the glass of water. 5. Observe from the side of the glass. 6. Continue to add the powder until the water becomes completely colored. Observations: You see streamers of color precipitate downward through the water. (Fall downward) Conclusion: The crystals dissolve in the water as they fall. Dissolving means a substance breaks apart into smaller and smaller particles and spreads out evenly throughout the solvent. The dissolving material, the solute, is the powdered crystals and the solvent is the water. The combination of a solute and a solvent produces a liquid solution. |
FOLLOW UP:
1. Have students complete all of the online activities.
2. Students are to choose five elements and list their properties.
Developed by Bonnie Glasgold, TeachNet, 2004