Introduction

Batteries are one of the most significant inventions in human history. Considered chemical sources of energy, they allow the conversion of chemical potential energy into electrical energy, being essential for the operation of various devices and appliances we use in our daily lives - from the TV remote control to the ignition system of a car.

The discovery of batteries occurred in the 19th century, by Alessandro Volta, an Italian physicist. He created the first electrochemical cell, known as Voltaic pile, which was a series of zinc and copper discs separated by cardboard discs soaked in saltwater. This discovery revolutionized the understanding of electric current.

At the heart of each battery, there is a redox chemical reaction, where the exchange of electrons occurs. This reaction is the source of the generated electric current. There are several types of batteries, each with its own structure, chemical composition, and operating principles, but all are based on this concept.

Contextualization

Batteries are present in numerous applications in our modern society. They are a fundamental part of electronic devices such as radios, flashlights, toys, alarms, computers, smartphones, among others. Furthermore, they are essential in sectors such as health, where they are used in pacemaker implants and portable medical equipment, and in the industry, where they are applied in sensors, alarm systems, measuring equipment, among others.

Understanding how batteries work is of vital importance for the education of a Chemistry student. It allows the student to connect with an integral part of modern technology and develop a greater appreciation for chemistry as a scientific field. In addition, education about batteries provides an opportunity for students to become familiar with important electrochemistry concepts, which will be useful in future studies and careers.

Practical Activity

Activity Title: "Batteries and the Moving World"

Project Objective

The objective of this project is to create a chemical battery using common everyday materials, calculating and observing in practice concepts such as anode, cathode, and cell potential difference (voltage) of the battery, as well as to better understand how batteries work in electronic devices.

Detailed Project Description

Groups of students, consisting of 3 to 5 members, will build a lemon battery to understand the operating principle of batteries. In addition, they must perform a series of tests and measurements to verify the production of electric current and understand how the energy conduction process occurs.

Materials Needed

• Lemons (3 to 5);
• Small pieces of zinc and copper;
• Copper wires with alligator clips on the ends;
• Digital multimeter to measure current and voltage;
• LED (Light Emitting Diode);
• Pliers;
• Protective gloves.

Step-by-Step for Activity Execution

1. Each group must cut a zinc and a copper into strips.
2. Next, both metals should be inserted into a lemon, taking care not to touch each other.
3. Connect a wire to the zinc strip and the other wire to the copper strip using the alligator clips, thus turning the lemon into an energy cell.
4. Repeat the procedure with other lemons. Each lemon will be an individual energy cell.
5. Organize the energy cells so that the copper of one cell is connected to the zinc of the next cell, forming a chain.
6. Using the multimeter, measure the electric current and generated voltage. Record the values.
7. Try to light the LED with the energy generated by the lemon battery. Record the results.
8. Write a project report highlighting the step-by-step process, the results obtained, and your conclusions.

Project Deliverables

Groups must submit a report on the project, with a minimum of 10 pages, including:

1. Introduction: Contextualize the project, explaining why batteries are important and how they work in the real world. Indicate what the project's objective was and what hypotheses were raised before the practical work.
2. Development: Discuss the step-by-step of the practical activity, describing the procedures adopted, the materials used, and the function of each battery component. Analyze and discuss the results of the tests performed - the current and voltage values, and the attempt to light the LED.
3. Conclusions: Make a critical analysis of the results obtained, relating them to the theory studied. Identify if the hypotheses were confirmed or refuted. Point out any difficulties encountered during the project and how they were resolved. Indicate the learnings obtained from the project execution, both in technical aspects and in terms of socio-emotional skills developed.
4. Bibliography: List all sources consulted during the project execution, including books, internet pages, videos, among others.

The report must be submitted in printed and bound form. All information must be presented clearly and objectively. The evaluation will take into account the technical quality of the report, the originality and depth of the analyses performed, and the presentation and organization of the information.

This project must be completed within 1 month, after which the groups must be ready to present their reports and share their findings with the class.