The periodic table of elements organizes all known chemical elements based on their physical and chemical properties. These properties help to distinguish between metals, non-metals, and metalloids. Metals are characterized by their ability to conduct electricity and heat, exhibit a metallic luster, and possess malleability. Non-metals, on the other hand, typically lack these properties, while metalloids display intermediate characteristics. This laboratory experiment aims to investigate the key physical and chemical properties of selected elements (zinc, sulfur, silicon, iron, and lead) and classify them accordingly. Additionally, the properties of alkali and alkaline earth metals will be examined to understand their unique chemical behaviors.
This hands-on activity introduces students to the scientific method, enabling them to observe, test, and classify elements based on their properties. By conducting experiments to measure electrical and thermal conductivity, observe metallic luster, test malleability, and evaluate reactivity with acid, students will gain practical experience in experimental science. The study of alkali and alkaline earth metals further enhances understanding of chemical families and their defining traits, encouraging analytical thinking and fostering a deeper appreciation for the periodic table.
Educational Goals
- Understanding physical and chemical properties: Students will explore the differences between metals, non-metals, and metalloids through direct observation and testing. They will learn how physical properties like conductivity, luster, and malleability, as well as chemical reactivity, distinguish these categories.
- Hands-on experimentation: Through guided experiments, students will gain practical experience in handling laboratory tools and materials, including conductivity detectors, clamps, and acids. This hands-on approach enhances their understanding of scientific concepts and methods.
- Developing analytical skills: Students will analyze experimental data to classify elements into appropriate categories. They will compare their results against known properties of metals, non-metals, and metalloids, fostering critical thinking and problem-solving abilities.
- Exploring chemical families: The properties of alkali and alkaline earth metals will be studied, emphasizing their distinct chemical behaviors. students will understand how these families interact with water and how their reactivity varies within the periodic table.
- Connecting theory to practice: By performing laboratory tests, students will bridge the gap between theoretical knowledge of the periodic table and practical application. this reinforces concepts learned in class and provides context for real-world scientific applications.
- Promoting safety and best practices: Students will follow laboratory safety protocols, including the use of protective equipment and proper handling of chemicals. This instills a culture of safety and responsibility in scientific work.
- Encouraging collaboration and teamwork: Working in pairs or small groups, students will share responsibilities for conducting experiments, recording data, and analyzing results. this collaborative approach mirrors professional scientific environments and enhances communication skills.
- Fostering curiosity and scientific inquiry: By exploring the periodic table through experimentation, students will develop a deeper curiosity about the natural world and a desire to further explore the principles of chemistry and material science.
By the conclusion of this laboratory activity, students will have gained a solid understanding of how physical and chemical properties define the classification of elements. They will also have strengthened their experimental, analytical, and collaborative skills, preparing them for more advanced scientific studies.
Protocol
The periodic classification of elements
Part A: The properties of metals, non-metals, and metalloids
Electrical conductivity
- Turn on the electrical conductivity detector (ECD).
- Take a sample of zinc using the tweezers.
- 3.Place the DCE electrodes on the piece of zinc (make sure that both electrodes are simultaneously in contact with the piece).
- Observe whether the DCE bulb lights up or not; the result can be found in the results table.
- Repeat steps 2 and 3 with pieces of sulfur, silicon, iron, and lead.
Thermal conductivity
- Take the zinc sample with the tweezers.
- Place the inside of the free hand on the piece of zinc in the tweezers. The result of the sensation is recorded in the results table.
- Repeat the steps with the pieces of sulfur, silicon, iron and lead.
Brightness
- Take the zinc sample with the tweezers.
- With the other hand, lightly rub the piece of zinc with the emery paper to remove any trace of dirt or oxidation on one of its parts.
- Observe the rubbed area; the observation is found in the results table whether it has a metallic shine or not.
- Repeat the steps with the pieces of sulfur; silicon; iron and lead.
Malleability
- Take the zinc sample with the tweezers.
- With the other hand, take the pliers and try to bend the zinc sample.
- Note the malleability in the results table. If the piece bends slightly, it means it is malleable. If it breaks, it means it is not.
- Repeat the steps with pieces of sulfur; silicon; iron and lead.
Reaction to acid
- Place a sample of the substances studied so far into a 50mL beaker already identified with their name.
- Pour a few drops of hydrochloric acid on the piece of zinc.
- Observe if a fizzing reaction occurs (presence of small bubbles). The reaction will be recorded in the results table.
- Repeat steps 2 and 3 with pieces of sulfur; silicon; iron and lead.
Part B: The properties of alkali and alkaline earth metals
Reaction with water
- In the beakers labeled lithium, sodium, potassium, magnesium, and calcium, pour 50mL of distilled water.
- Confirm the neutrality of the water used in the beakers by dipping a piece of red litmus paper and a piece of blue litmus paper into it.
- Place a sample of the substances lithium, sodium, potassium, magnesium and calcium in a 50mL beaker already labeled with their names, containing distilled water.
- Soak a piece of red litmus paper and a piece of blue litmus paper in the beakers again.
- Repeat step 4 with the 4 other substances.
Anticipated Outcomes
| Element | Zn | S | Si | Fe | Pb | Li | Na | K | Mg | Ca |
| Electrical conductivity | Yes | No | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Thermal conductivity | Yes | No | No | Yes | Yes | No | No | No | No | No |
| Metallic shine | Yes | No | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Malleability | Yes | No | No | Yes | Yes | Yes | Yes | Yes | No | No |
| Acid reaction | Yes | No | No | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Reaction with water | No | No | No | No | No | Yes | Yes | Yes | No | Yes |
- Identification of Element Properties
- Students will accurately observe and record the electrical conductivity, thermal conductivity, luster, malleability, and reactivity of zinc, sulfur, silicon, iron, and lead. These observations will enable them to classify the elements as metals, non-metals, or metalloids.
- Understanding Chemical Family Characteristics
- Through experimentation, students will identify the unique behaviors of alkali and alkaline earth metals when reacting with water. They will note variations in reactivity, allowing them to draw connections between an element’s position on the periodic table and its chemical behavior.
- Skill Development
- Students will enhance their practical laboratory skills, including accurate measurement, use of specialized equipment, and proper handling of chemical reagents. These skills will support their future scientific endeavors.
- Data Analysis and Interpretation
- Students will learn to analyze experimental results critically and compare their findings to theoretical expectations. This will deepen their understanding of the periodic table and material properties.
- Application of Safety Protocols
By adhering to safety guidelines, students will demonstrate the ability to conduct experiments responsibly, an essential competency for working in any laboratory environment.
Summary of Assignment by Grade Range
Summary of Assignment by Grade Range
Grades 6-8
Focus: Building foundational skills and understanding element properties.
- Students will complete basic tests on electrical conductivity, thermal conductivity, luster, and reactivity.
- Observations will be simple, with a focus on identifying trends and making basic classifications of elements.
Expected Outcomes:
- Understanding of key physical and chemical properties.
- Improved ability to follow instructions and document results.
- Introduction to periodic table trends and classifications.
Grades 9-10
Focus: Expanding analytical abilities and exploring chemical families.
- Students will perform more detailed analyses, including comparisons between alkali and alkaline earth metals.
- They will learn to interpret experimental data within the context of periodic table trends.
Expected Outcomes:
- Development of hypothesis-testing and critical analysis skills.
- Application of periodic trends to predict element behavior.
- Enhanced collaboration through group experiments.
Grades 11-12
Focus: Advanced experimentation and synthesis of knowledge.
- Students will conduct comprehensive experiments, integrating multiple data points to classify elements and understand periodic trends.
- They will produce detailed lab reports, including introductions, methodologies, and critical evaluations of their results.
Expected Outcomes:
- Mastery of laboratory protocols and safety measures.
- Ability to produce professional-quality scientific reports.
- In-depth understanding of the periodic table and its applications in chemistry and material science.
By structuring the assignment to align with students’ developmental stages, this laboratory activity ensures that learners at all levels can engage meaningfully with the content and build essential skills for future scientific studies.
Laboratory essentials
Instruments
Electrical conductivity detector (DCE)
Metal pliers
Red & Blue litmus papers
Emery paper
Paper towel
50mL beakers x5
100mL beakers x5
Dropper
pH chart
Products
HCl 1M solution
Zinc (s)
Sulfur (s)
Silicon (s)
Iron (s)
Lead (s)
Lithium (s)
Sodium (s)
Potassium (s)
Magnesium (s)
Calcium (s)