Final answer:
The property of matter that is conserved in chemical reactions and shown by balanced equations is mass, as per the law of conservation of mass, which ensures the total mass of the reactants equals the mass of the products.
Step-by-step explanation:
The property of matter that is conserved in chemical reactions and shown by balanced equations is mass. In a chemical reaction, the quantity of each element remains unchanged, meaning there is the same amount of each element in the products as there was in the reactants. This is a reflection of the law of conservation of mass, which states that the total mass of the products must be equal to the total mass of the reactants. Therefore, a correctly balanced chemical equation will have the same number of atoms of each element on both sides of the equation, illustrating that mass is conserved.
For instance, when water (H₂O) is formed from hydrogen (H₂) and oxygen (O₂), the balanced chemical equation is 2H₂(g) + O₂(g) → 2H₂O(l). In this equation, we have two molecules of hydrogen gas reacting with one molecule of oxygen gas to produce two molecules of water, conserving mass as both sides have four hydrogen atoms and two oxygen atoms.