Its all about particles
What are atoms?
The tiny building blocks that make up all matter.
What is a chemical reaction?
A process in which atoms rearrange to form new substances.
What visible evidence did we observe when the bath bomb was placed in water?
Fizzing or bubbling.
What is the chemical formula for water?
H₂O.
What does conservation of matter mean?
Matter is not created or destroyed during a chemical reaction.
What is a molecule?
Two or more atoms chemically bonded together.
Name one observation that could provide evidence of a chemical reaction.
Gas production, a temperature change, a color change, or formation of a new solid.
What gas is produced by the reaction in a typical baking soda and citric acid bath bomb?
Carbon dioxide (CO₂).
When liquid water is heated until it becomes water vapor, is a new substance formed?
No. Water vapor is still H₂O.
What happens to atoms during a chemical reaction?
They rearrange and form new combinations.
What is the difference between an atom and a molecule?
An atom is one particle of an element; a molecule contains two or more bonded atoms.
Why can bubbling be evidence of a chemical reaction but not proof by itself?
Bubbles can also form during physical changes, such as boiling.
Why did we investigate the gas released from the bath bomb?
To identify the gas and use evidence to understand the chemical reaction.
What happens to water molecules when liquid water changes into a gas?
The molecules move farther apart and spread out, but remain H₂O.
Why should the total mass stay the same during a reaction in a closed system?
All the atoms remain inside the system, so the total amount of matter stays the same.
How is a water molecule different from an oxygen gas molecule?
Water is H₂O, with two hydrogen atoms and one oxygen atom. Oxygen gas is O₂, with two oxygen atoms.
How can you tell that a chemical reaction has produced a new substance?
Evidence shows the products have different chemical identities or properties from the starting substances.
Why is the gas produced by the bath bomb considered matter?
It has mass and takes up space, even though it may be invisible.
How is adding electrical energy to water different from simply heating it?
Electrical energy can cause water to decompose into hydrogen and oxygen gases, while heating produces water vapor.
A model has four hydrogen atoms before a reaction and only two afterward. What is wrong?
The model violates conservation of matter because two hydrogen atoms are missing.
A model shows H₂O before a reaction and H₂ and O₂ afterward. What must be checked to decide whether the model is scientifically accurate?
The number of hydrogen and oxygen atoms must be equal before and after the reaction.
A student says, 'The bath bomb disappeared because the bubbles carried away all its matter.' Explain why this claim is incorrect.
The matter did not disappear. Atoms were rearranged into products, including gas that escaped into the air.
A bath bomb reacts in an open container, and the measured mass decreases. Does this mean matter was destroyed? Explain.
No. Gas escaped from the open container, so some matter was no longer included in the measurement.
A student claims the bubbles from boiling water and electrolysis contain the same molecules. Use particle evidence to evaluate the claim.
The claim is incorrect. Boiling produces H₂O vapor, while electrolysis produces H₂ and O₂ molecules.
A student says a chemical reaction creates brand-new atoms. Use a before-and-after particle model to explain the error.
The same types and numbers of atoms must appear before and after. Chemical reactions rearrange existing atoms rather than creating new ones.
Mark complete and return to board Final Jeopardy