Final answer:
A battery stores and converts chemical potential energy into electrical energy used in circuits. It goes flat when all energy is converted into other forms. Environmental regulations like Directive 2006/66/EC limit the use of harmful substances like cadmium in batteries to improve environmental performance.
Step-by-step explanation:
The concept of a battery pertains to its ability to store chemical potential energy and convert it into electrical energy, which is used to power electronic devices within a circuit. When a battery is connected to a circuit and a chemical reaction occurs internally, it changes the chemical potential energy into electrical energy that moves electrons through the circuit.
The elements within the circuit, such as resistors and lightbulbs, offer resistance to the flow of charge and transform the electrical energy into other forms like heat and light. Once the stored chemical potential energy in the battery has been fully converted, the battery is considered flat or depleted.
There are also environmental concerns regarding batteries, specifically the content of hazardous materials they may contain. For instance, the Directive 2006/66/EC by the European Union set regulations to limit the amount of cadmium in portable batteries to improve environmental performance.
This directive states that batteries should not contain more than 0.002% of cadmium by weight, underscoring the consideration of environmental impact in battery design and disposal.