<h2>Answer;</h2>
Light is produced and heat is produced
<h2>Explanations</h2>
Chemical changes occurs when substances react to form new products. This reaction can be in form of a decomposition reaction.
During fireworks explosion, there is a reaction between charge of gunpowder which is been ignited with a fuse to produce a spark that leads to explosion.
The explosion leads to production of light and heat. Hence we can conclude that some signs that a chemical change takes place when a firework explodes is light is produced and heat is produced
Answer is: <span>the acidity of water reduce the mass of seashells.
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Balanced chemical reaction:
CaCO₃(s) + 2HCl(aq) → CaCl₂(aq) + CO₂(g) + H₂O(l).
Calcium carbonate (CaCO₃) dissolves in hydrochloric acid and gas carbon(IV) oxide is formed.
Calcium carbonate is inorganic salt insoluble in water, but soluble in acidic solutions.
As oceanic crust moves away from shallow mid ocean ridges, it cools and sinks as it becomes more dense. Hope this helped have a good day!