Define the law of conservation of mass.

The law of conservation of mass is a fundamental principle in chemistry and physics. It states that in a closed system, the total mass of substances remains constant, regardless of the processes occurring within that system. This means that matter cannot be created or destroyed; it can only change forms.

Key Points of the Law

• Closed System: The law applies only when no mass enters or leaves the system.
• Mass Change: While substances may transform during chemical reactions, their total mass before and after the reaction remains the same.
• Historical Significance: This principle was established by Antoine Lavoisier in the 18th century, laying the groundwork for modern chemistry.

Real-World Examples

Consider a simple reaction like burning wood. The wood transforms into ash, gases, and heat. Although the wood appears to disappear, the total mass of the resulting products equals the mass of the original wood plus the oxygen consumed during combustion.

Importance in Science

This law is crucial for balancing chemical equations, conducting experiments, and understanding various scientific processes. It helps scientists predict how substances will interact and the outcomes of reactions.