1. During the process of iron rusting, an iron atom combines with oxygen atoms. What is the identity of that original iron atom after the reaction is complete?
- A. It has been transformed into an oxygen atom.
- B. It is still an iron atom, but it is now bonded differently.
- C. It has been destroyed and converted into energy.
- D. It has become a new, fundamental type of atom called a 'rust' atom.
2. A hydrogen atom from a water molecule (H₂O) is used by a plant during photosynthesis to help create a sugar molecule (C₆H₁₂O₆). Which statement accurately describes the hydrogen atom?
- A. The hydrogen atom was converted into a carbon atom.
- B. The hydrogen atom retained its identity throughout the process.
- C. The hydrogen atom was broken down into smaller particles.
- D. The hydrogen atom merged with an oxygen atom to form a new element.
3. If you could track a single carbon atom through the entire carbon cycle, from a plant to an animal that eats it, and then into the atmosphere after the animal exhales, what would you observe about the atom's identity?
- A. The atom would be a carbon atom at all times.
- B. The atom would change into a nitrogen atom in the animal.
- C. The atom would be destroyed and remade at each step.
- D. The atom would temporarily become an oxygen atom in the atmosphere.
4. If the individual atoms that make up a substance do not change their identity during a chemical reaction, why do we observe the formation of a completely new substance?
- A. Because the atoms change their size and mass.
- B. Because the atoms rearrange themselves into new repeating groups or molecules.
- C. Because the number of protons in the atoms' nuclei changes.
- D. Because the original substance's atoms are replaced by new atoms from the air.
5. What is the key difference between the 'fundamental building blocks' and the 'macroscopic substance' during a chemical reaction?
- A. The building blocks get smaller, while the substance gets larger.
- B. The building blocks (atoms) are destroyed, while the substance is created.
- C. The building blocks (atoms) remain the same, while the substance (their arrangement) changes its properties.
- D. The building blocks change identity, while the substance maintains its original properties.
6. If a chemical reaction begins with 50 oxygen atoms and 100 hydrogen atoms to form water, how many oxygen atoms will be found in the water molecules produced?
- A. More than 50
- B. Exactly 50
- C. Fewer than 50
- D. Zero
7. A teacher uses the analogy of taking apart a bicycle to build a scooter. In this analogy, what do the individual parts like wheels, handlebars, and pedals represent?
- A. The chemical reaction
- B. The atoms
- C. The products
- D. The chemical bonds
8. What is the fundamental principle of 'atomic rearrangement' in chemistry?
- A. Atoms change their mass and charge to form new substances.
- B. The total number and type of atoms remain the same during a reaction.
- C. Atoms from the reactants are permanently lost when products are formed.
- D. New atoms are created to meet the needs of the chemical product.
9. Which statement best describes what happens to atoms during a chemical reaction?
- A. Some atoms are destroyed, and new ones are created.
- B. Atoms change their identity, becoming atoms of a different element.
- C. Atoms are rearranged into new combinations, but are not created or destroyed.
- D. The atoms are converted entirely into energy.
10. In the reaction that forms table salt (NaCl) from sodium (Na) and chlorine (Cl₂), what must happen for the new substance to be created?
- A. The bond between chlorine atoms must break before new bonds with sodium can form.
- B. Sodium atoms must be converted into chlorine atoms.
- C. New atoms of salt must be spontaneously generated.
- D. The original atoms must be destroyed to release energy.