Atoms in a Chemical Reaction
Atoms in a chemical reaction are neither lost nor destroyed. This fundamental principle is known as the Law of Conservation of Mass, which states that the total mass of the reactants must be equal to the total mass of the products in a chemical reaction.

Explanation:
- When a chemical reaction occurs, atoms are rearranged to form new substances.
- However, the number of atoms of each element must remain the same before and after the reaction.
- This means that no atoms are lost or destroyed during the process.

Example:
- Consider the reaction between hydrogen gas (H2) and oxygen gas (O2) to form water (H2O).
- The equation for this reaction is: 2H2 + O2 -> 2H2O
- In this reaction, the total number of hydrogen atoms and oxygen atoms remains the same on both sides of the equation.

Conclusion:
- The Law of Conservation of Mass ensures that atoms are conserved in a chemical reaction, even though they may undergo changes in bonding and arrangement.
- This principle is crucial in understanding and predicting the outcomes of chemical reactions.

Physical