Chemical and Physical Change
When a bath bomb fizzes, what kind of change is happening?
A chemical change — new substances form.
What type of system is it when a bath bomb fizzes in an open cup of water?
An open system — gas can escape into the air.
What two main substances make up a bath bomb and react to cause fizzing?
Baking soda (sodium bicarbonate) and citric acid.
What does the Law of Conservation of Matter say?
Matter cannot be created or destroyed — only rearranged.
What kind of scientist studies how different substances react and form new ones, like in a bath bomb?
A chemist — they investigate how substances change during chemical reactions.
What evidence shows the change is chemical, not physical?
Bubbles and gas form, which means a new substance (CO₂) is created.
What type of system is it when a bath bomb fizzes in a sealed flask with a balloon attached?
A closed system — no matter leaves or enters.
What happens when citric acid is mixed with baking soda before water is added?
Nothing — they stay the same because a liquid is needed to allow the atoms to interact.
During the bath bomb reaction, why might it seem like some matter disappears?
Because CO₂ gas escapes, but those atoms still exist — they just move into the air.
What type of scientist would study the bubbles and gases released when a bath bomb fizzes in water?
A physical chemist — they study energy, gas formation, and the behavior of matter during reactions.
Is dissolving citric acid in water before reacting chemical or physical?
Physical change — the acid dissolves but doesn’t form a new substance.
Why does the mass seem to decrease when a bath bomb reacts in an open system?
The carbon dioxide gas escapes into the air, so it’s no longer part of the measured mass.
Which property of baking soda allows it to react easily with an acid?
It is a base, meaning it reacts with acids to form new substances.
What evidence from the balloon investigation supports conservation of matter?
The mass stayed the same before and after the reaction in a closed system.
What kind of scientist designs safe, skin-friendly bath products using chemical reactions like the one in bath bombs?
A cosmetic or formulation chemist — they apply chemistry to create products that react safely and smell good.
How does adding water allow the chemical reaction to begin?
Water lets the acid and base particles move and collide, breaking and reforming bonds.
Why does the mass stay the same when the reaction happens in a closed system?
The gas stays trapped inside, so all atoms and products remain in the system.
Before reacting, how could you tell baking soda and citric acid are two different substances?
They have different properties like taste, solubility, and pH even though both are white powders.
At the atomic level, what happens during the bath bomb reaction?
Atoms rearrange from citric acid and baking soda to form new molecules like CO₂, H₂O, and sodium citrate.
Which type of scientist might investigate how pollutants or water chemistry affect how bath bombs react or dissolve?
An environmental chemist — they study how chemicals interact with water, air, and the environment.
Explain how both physical and chemical changes occur when a bath bomb reacts.
The bath bomb dissolving is a physical change, while CO₂ gas formation and temperature change are chemical changes that produce new substances.
Compare the open and closed bath bomb systems. What do the results show about how matter moves during chemical reactions?
In both systems, atoms are conserved, but in the open one, gas moves out of the container. In the closed system, all products stay inside, showing mass is conserved even when matter changes form.
During the reaction, how do you know new substances formed instead of just mixing?
The properties changed — bubbles, gas, and temperature change showed a chemical reaction occurred, producing new substances.
If the total mass before and after a closed-system reaction is the same, what does that tell us about the particles?
All atoms are still present; they just rearranged into new combinations, proving mass and matter are conserved.
A team of scientists wants to make a more eco-friendly bath bomb that produces less CO₂ gas but still fizzes. What kinds of scientists might work together, and what would each study?
A chemical engineer would design and test new materials, a chemist would study the reaction and product safety, and an environmental scientist would study how the new ingredients affect ecosystems. Together, they’d use chemistry to reduce gas emissions while keeping the fizzing reaction effective.