FUN WITH THE PERIODIC TABLE

Activity 1 Organizing a Store

Engage-What Do You See?

What Do You Think? Some supermarkets now sell books,

flowers, and prescription drugs in addition to eggs, meat, and cereal. How many different items do you think

that a supermarket has?

Explore- Investigate 1. Suppose that you decided to go into the

business of opening and running a supermarket. In your group, brainstorm a list of between 50 and 100 items you would sell at your supermarket. A member of your group should volunteer to record the items suggested by all members of the group. Everyone, including the person serving as recorder, should participate. a) Make a map showing the locations of all of the items in

your store. Give some thought to what will be at the front of each aisle, and what will be at the back. Consider how the store will be arranged from left to right.

b) Keep in mind which items you want shoppers to see as they enter the store and which should be near as they approach the cash register. Would either of these factors alter your arrangement?

c) Consider the items from left to right across your store. Why did you choose to arrange the items that way?

What Do You Think Now?

At the beginning of the activity, you were asked to think about the question:• How many different items do you

think that a supermarket has? When you get used to one supermarket, it

becomes easier to navigate your way. Would your supermarket be easy to

navigate? Why?

Explain- Chem Talk

Organizing 50 to 100 items in your store is not unlike the problem faced by Mendeleev when he organized about the same number of chemical elements into the periodic table. This activity was designed to get you to understand some of the problems Mendeleev faced. It is hoped that you can better appreciate what he did.

The Periodic Table Revisited Dmitri Mendeleev arranged the elements

in 1871. He based his arrangement on the atomic mass of the elements and the common properties. He suggested that the properties of the elements was a function of their atomic masses, however, he believed that similar properties occur after periods that could vary in length. He also left some blank spots in the order to suggest that there were elements yet to be discovered. He stated that the properties of the elements are a periodic function of their atomic mass and this was called the periodic law.

This was the first periodic table of the elements, but it still had some problems.

Periodic Table Development In 1913, Henry Mosley

rearranged the table according to increasing atomic number. This corrected the problems with Mendeleev’s periodic table.

Mosley’s change allowed the elements to be organized into groups with similar chemical and physical properties.

This lead to the development of the modern periodic table and to the development of the Periodic Law.

Henry Moseley found exceptions to Mendeleev’s periodic law. The discovery of the subatomic particles affected the arrangement of the elements of the periodic table. The atomic number (mainly electrons) is the now how the table is arranged. The electrons are what determine the chemical and physical properties of the elements. Elements are classified in four categories based on electron configuration. a. Noble Gases b. Representative Elements c. Transition Metals d. Inner Transition Metals

Periodic Table Organization - Rows A horizontal row of elements in the periodic table is

called a period. Changes in size, character and properties can be found

by moving across a period. Periods are labeled with a single number.

Periodic Table Organization - Columns A vertical column of elements in the periodic table is called a group or family.

Elements within the same group or family have similar chemical and physical properties.

Groups are labeled with an Arabic number or a Roman numeral and a letter.

Periodic Table Ogranization - Columns The major group or families on the periodic table include;

-The Alkali Metals - Group 1 (IA)

-The Alkaline Metal Earth's - Group 2 (IIA)

AlkaliMetals

Alka

line

Eart

h M

etal

s

Periodic Table Ogranization - Columns

-The Transition Metals - Groups 3 thru 12 (IB thru VIIIB)

-The Inner Transition Metals - The Lanthanide and Actinide Series

-The Halogens - Group 17 (VIIA)

-The Noble Gases - Group 18 (VIIIA)

Transition metals

Inner TM

Inner TM

halo

gen

s

Nobel G

ase

s

3 Types Element-Metals - Located to the left and below the zig-zag line(staircase)

-Nonmetals - Located to the right and above the zig-zag line(staircase)

-Metalloids - Located along each side of the zig-zag line(staircase)

Natural and Man-made Elements Elements with atomic numbers from 1 to 92 occur

naturally.

Elements with atomic numbers above 92 are man-made elements. These elements are known as the transuranic elements since they are located after the last naturally occurring element, uranium.

Elements with parenthesis around their atomic masses are radioactive.

States of Elements Gases: 11 elements exist as gases at room temperature. These

are hydrogen (H), helium (He), nitrogen (N), oxygen (O), fluorine (F), neon (Ne), chlorine (Cl), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).

Solids: The remaining elements are solids at room temperature.

Liquids: Only two elements are true liquids; mercury (Hg) and bromine (Br).

Evaluate You are to write 5 questions using the Chem Talk

information given. 3 can be simple one sentence answers 2 must require at least 2-3 sentences to answer your question.

1. What is the pattern or arrangement in your store’s aisles?

2. Choose one aisle in your store. Describe the arrangement of items going from the front of the store to the back of the store. What is the trend (or general drift) in that aisle?

3. A new item is brought into the store — chocolate-covered peanuts. Where would you place this item? Provide an explanation for your decision.

4. Your store decides to sell napkins, plates, and decorations for Thanksgiving. How will you adapt your store arrangement to make room for these items?

5. One of the characteristics of Mendeleev’s original periodic table was a series of blank spots. Mendeleev expected these would eventually be filled with elements yet to be discovered. What would such a “blank” correspond to in your store?

FUN WITH THE PERIODIC TABLE

Activity 2 Element and their Properties

Engage 2-What Do You See?

What Do You Think?

Throughout history, philosophers and scientists have talked about “the elements.” Reference to elements is most frequent today in the field of chemistry. What is an element?

RESULTS FOR INVESTIGATE

Element Initial observation

Conductselectricity

Reactswith HCl

Magnetic ornonmagnetic

Metal ornonmetal

aluminum

carbon

copper

iodine

iron

magnesium

sulfur

zinc

Explore- InvestigateCopy the following table in your journal.

Explore-Investigate

1. Your teacher will provide samples of the following common elements: aluminum, carbon, copper, iodine, iron, magnesium, silicon, sulfur, and zinc. You will investigate the properties of these elements. By observing common properties, you may gain an insight into how an organizational chart can be created for all of the known elements. Observe the sample of the chemical element in each jar (without removing any). You can describe this initial observation of each element in the first column of a table similar to the one shown. a) Record your observations in a table.

Investigate

2. One of the properties of the elements on Mendeleev’s cards was the ability of the element to conduct electric current. Some materials can conduct electricity while others cannot. Using a conductivity meter, you will be able to complete the third column of the chart. a) Test the samples of each element with

the electrical conductivity apparatus. Record whether the element conducts electric current, (yes) or (no).

b) Based on your initial observation and the results of the conductivity test, can you suggest a way to group the elements? Describe an arrangement in your log.

Investigate 3. Another property of each element known to

Mendeleev was how it reacts with an acid. Pour 5 mL of 3 M hydrochloric acid (HCl) into each of

nine small test tubes. (3 M is an indication of the concentration of the acid.) Use a scoop or tongs to remove a small portion of each element from the jar and add it to the hydrochloric acid. It is important to add the hydrochloric acid to the test tube first so that you will not be surprised by a reaction that occurs when you pour acid over a reactive element. Place a piece of white paper in the background behind the test tube and observe the reaction between the element and hydrochloric acid by looking through the side of the test tube. a) Test a small sample of each element for its

reaction with hydrochloric acid (HCl). Record whether it reacts with the acid, (yes) or (no).

b) For those elements that do react, try to determine whether all show the same type of reaction. (Do they all do the same thing?) Compare the relative vigor of the reactions. If the reaction is vigorous, include a sign next to your “yes.” If the reaction is weak, place a sign next to your “yes.”

Investigate 4. Dispose of the contents of the test tubes and clean the

test tubes as directed by your teacher. Now that three columns of observations are included in the table, describe a way to arrange the different elements.

5. Place a small amount of each sample on a watch glass. Use a magnet and test the element to see if it is attracted to the magnet. Record your observations in your table.

6. A metal is generally a solid that is shiny, malleable, and a good conductor of heat and electricity. Nonmetals have a wide range of properties. Some are dull and brittle, but others, like diamond, are hard and brilliant, and still others are gases or liquids. Most are poor conductors of electricity. Classify each of the elements you observed as either a metal or nonmetal. Record your observations in the table in your Active Chemistry log.

Analysis

4. Dispose of the materials as directed by your teacher. Clean up your workstation.

5. Compare and contrast your arrangement with that of another group. a) In what two ways are the arrangements

similar? b) In what two ways are the arrangements

different? c) Which of these two arrangements do you

think better allows you to quickly find if an element conducts electricity, reacts with HCl, or is metallic?

Explain- Chem Talk Read pp. 11 and 12 and answer the questions. 1. Define an element. 2. What question did Mendeleev use to guide his science

inquiry? 3. In your own words, describe the difference between a

physical and a chemical property. 4. Knowledge of how the elements are classified or grouped

is an important component of your game. How can arranging elements by conductivity and other properties?

5. Because different elements possess different properties, they have many different uses. For example, since copper metal is a good electrical conductor, it is used in speaker wiring. Choose two of the elements you worked with in this activity and suggest a use for them based on a particular property they exhibit.

Evaluate- Chem to Go

Do the Chem-to-Go on p. 14. Answer questions 1-8