Alkali Metals Worksheet for 12-Year-Olds | Science & Chemistry

Instructions

1. Read each section carefully and complete the activities in order.
2. Use a periodic table when asked. Remember that alkali metals are found in Group 1, not including hydrogen.
3. Write complete answers when a question asks you to explain.
4. Complete the Challenge Mission if you want to stretch your thinking.

Learning goals: By the end of this worksheet, you should be able to:

• Locate alkali metals on the periodic table.
• Identify their shared physical and chemical properties.
• Explain why their reactivity changes down the group.
• Connect their position to their electron arrangements and uses.

1. Meet the Alkali Metals

The alkali metals are the elements in Group 1 of the periodic table, except for hydrogen. The main alkali metals are:

• Lithium, Li
• Sodium, Na
• Potassium, K
• Rubidium, Rb
• Cesium, Cs
• Francium, Fr

They are called alkali metals because they react with water to make alkaline solutions.

A. Locate and Label

Use a periodic table to complete the sentences.

1. Alkali metals are found in Group __ of the periodic table.
2. The alkali metal in Period 2 is ____.
3. The chemical symbol for sodium is __.
4. The alkali metal in Period 4 is ____.
5. The element below potassium in Group 1 is ____.
6. Hydrogen is located above Group 1, but it is not / is an alkali metal. Circle the correct answer.

B. Group 1 Detective Table

Example: The first row shows how to record information. Use a periodic table to complete the remaining rows.

2. Property Sort

Decide whether each statement describes an alkali metal. Write A for “usually true of alkali metals” or N for “not usually true.”

1. __ They have one outer-shell electron.
2. __ They are very unreactive.
3. __ They are soft enough to cut with a knife.
4. __ They are found in Group 17.
5. __ They usually form ions with a +1 charge.
6. __ They become more reactive down Group 1.
7. __ They are good conductors of heat and electricity.
8. __ They commonly react with water.
9. __ They are all gases at room temperature.
10. __ They are metals.

Explain Your Choice

Choose one statement that you marked A and explain why it is useful for identifying an alkali metal.

3. Periodic Table Connection

A. Multiple Choice

Circle the best answer.

1. What do elements in the same group usually have in common?

   a. The same atomic mass
   b. Similar chemical properties
   c. The same number of electron shells
   d. The same symbol

2. Why do alkali metals usually form +1 ions?

   a. They gain one electron.
   b. They lose one outer-shell electron.
   c. They have no electrons.
   d. They gain seven electrons.

3. Which element is most likely to be the most reactive?

   a. Lithium
   b. Sodium
   c. Potassium
   d. Cesium

4. Which pair contains only alkali metals?

   a. Sodium and chlorine
   b. Magnesium and potassium
   c. Lithium and potassium
   d. Calcium and cesium

5. Which statement about Group 1 is correct?

   a. Reactivity generally increases down the group.
   b. Reactivity generally decreases down the group.
   c. All Group 1 elements are gases.
   d. Group 1 elements have seven outer-shell electrons.

B. Electron Clue

A neutral sodium atom has the electron arrangement 2, 8, 1.

1. How many electron shells does sodium have? __
2. How many outer-shell electrons does sodium have? __
3. Does sodium tend to gain or lose electrons? ____
4. What charge does a sodium ion usually have? __
5. Complete the symbol for the ion: Na __

4. Reactivity Investigation: Why Does It Change?

Alkali metals become more reactive as you move down Group 1. Their outer electron is farther from the nucleus in atoms with more electron shells. The attraction between the nucleus and that outer electron becomes weaker, so the electron is easier to lose.

A. Put in Order

Number these elements from 1 = least reactive to 4 = most reactive.

• __ Cesium
• __ Lithium
• __ Potassium
• __ Sodium

B. Complete the Explanation

Use the word bank to complete the paragraph.

Word bank: farther, easier, outer, increases, shells

As you move down Group 1, the number of electron __ increases. The __ electron is __ from the nucleus. The attraction is weaker, so the electron is __ to lose. Therefore, reactivity generally __ down the group.

C. Predict the Reaction

Imagine that equal-sized pieces of lithium, sodium, and potassium are placed separately in water by a trained scientist using appropriate safety equipment.

1. Which metal would probably react most gently? ____
2. Which metal would probably react most vigorously? ____
3. What gas is commonly produced when an alkali metal reacts with water? ____
4. Why should students never try this experiment without a trained teacher?

5. Real-World Mission: Choose the Best Metal

A science team needs to select a Group 1 element for each situation. Use the clues to make a reasonable choice. Some choices may have more than one possible answer, but explain your thinking.

1. A research team wants a relatively less reactive alkali metal for a demonstration. Which common alkali metal would be the best choice: lithium, sodium, or potassium?

   Choice: ____

   Reason: ____

2. A company needs sodium compounds for making salt substitutes, soaps, or glass. Which element is connected to these compounds?

   Choice: ____

   Reason: ____

3. A spacecraft designer is investigating a very light metal. Which alkali metal would be a useful element to investigate?

   Choice: ____

   Reason: ____

4. Why are pure alkali metals usually stored carefully rather than left exposed to air and water?

6. Matching Challenge

Match each term in Column A with the best description in Column B. Write the letter on the line.

7. Draw and Think

Draw a simple periodic table outline. Shade or circle Group 1. Label the following elements in their correct positions:

Li, Na, K, Rb, Cs, Fr

Then answer the questions.

1. What pattern do you notice in the positions of the alkali metals?

2. Why do elements in the same group often have similar chemical behavior?

3. What happens to the number of electron shells as you move down Group 1?

Challenge Mission: Think Like a Chemist

Francium is below cesium in Group 1, but it is extremely rare and radioactive. Based on the Group 1 trend, predict whether francium would be more or less reactive than cesium. Then explain why scientists may not be able to test this easily in a school laboratory.

Prediction: __

Explanation: __

Quick Review

Complete the five-sentence summary.

1. Alkali metals are found in Group __.
2. They have __ outer-shell electron.
3. They usually form ions with a __ charge.
4. Their reactivity generally ____ down the group.
5. Alkali metals must be handled carefully because they can react with ____ and produce heat and gas.

Answer Key

1. Meet the Alkali Metals

A. Locate and Label

1. 1
2. Lithium
3. Na
4. Potassium
5. Rubidium
6. is not

B. Group 1 Detective Table

2. Property Sort

1. A
2. N
3. A
4. N
5. A
6. A
7. A
8. A
9. N
10. A

The explanation will vary. A strong answer could say: “Alkali metals have one outer-shell electron, which helps identify them because all elements in Group 1 share this electron pattern.”

3. Periodic Table Connection

A. Multiple Choice

1. b. Similar chemical properties
2. b. They lose one outer-shell electron.
3. d. Cesium
4. c. Lithium and potassium
5. a. Reactivity generally increases down the group.

B. Electron Clue

1. 3
2. 1
3. Lose electrons
4. +1
5. Na+

4. Reactivity Investigation

A. Put in Order

• Cesium: 4
• Lithium: 1
• Potassium: 3
• Sodium: 2

B. Complete the Explanation

As you move down Group 1, the number of electron shells increases. The outer electron is farther from the nucleus. The attraction is weaker, so the electron is easier to lose. Therefore, reactivity generally increases down the group.

C. Predict the Reaction

1. Lithium
2. Potassium
3. Hydrogen
4. A strong answer should mention that the reaction can release heat, produce flammable hydrogen gas, and possibly cause fire or an explosion. Proper laboratory equipment, training, and supervision are required.

5. Real-World Mission

1. Lithium. It is generally less reactive than sodium and potassium.
2. Sodium. Sodium compounds are used in products such as glass, soaps, and salt substitutes.
3. Lithium. It is the lightest metal and is used in some batteries and other technologies.
4. Pure alkali metals are stored carefully because they can react with moisture in the air or with water. These reactions can release heat and produce hydrogen gas.

6. Matching Challenge

1. B
2. A
3. D
4. C
5. E

7. Draw and Think

1. The elements form a vertical column in Group 1.
2. They have similar outer electron arrangements, especially one outer-shell electron.
3. The number of electron shells increases.

Challenge Mission

Francium would be predicted to be more reactive than cesium because it is lower in Group 1 and its outer electron would be farther from the nucleus and easier to remove. Testing this is difficult because francium is extremely rare, radioactive, and exists only in tiny amounts.

Quick Review

1. 1
2. one
3. +1
4. increases
5. water