4 original questions from New Regents. The worksheet, answer key, and browser practice are free.
Comparing Grain Contacts in a Model Sample 4 questions
Comparing Grain Contacts in a Model Sample
Base your answers on the information provided and your knowledge of chemistry. Use the 2025 Chemistry Reference Tables as needed.
A classroom display compares equal masses of two powders, P and Q. Students measure how easily electric charge moves through one grain and through a container filled with many grains. The powder container has contacts on its two ends. A continuous chain of touching conducting grains can carry charge between the contacts.
| Sample | A single grain conducts | Loose bed conducts | Pressed bed conducts |
|---|---|---|---|
| P | Yes | No | Yes |
| Q | No | No | No |
Question 1
Which evidence supports a change in contact pathways when P is pressed?
- An individual grain of P conducts, and only the pressed bed of P conducts.
- Both the loose and pressed beds of Q fail to conduct.
- A single grain of Q fails to conduct.
- Both loose beds fail to conduct.
Question 2
Explain why an individual P grain can conduct when the loose bed cannot conduct from one end to the other.
Write your answer and work on the printable worksheet, or answer online.
The class keeps the pressed P grains in place. A thin barrier that does not conduct is placed across the middle of the bed. It separates all the grains on one side from all the grains on the other side.
Question 3
Predict whether the entire bed conducts from contact to contact after the barrier is added. Explain using the grain model.
Write your answer and work on the printable worksheet, or answer online.
Question 4
Describe how to test whether pressing permanently changed the conductivity of the individual P grains. Explain what result would support the contact-path model.
Write your answer and work on the printable worksheet, or answer online.
2025 Chemistry Reference Tables · Browse Chemistry worksheets