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Two Ions With the Same Mass Number 4 questions
Two Ions With the Same Mass Number
Base your answers on the information provided and your knowledge of chemistry. Use the 2025 Chemistry Reference Tables as needed.
A classroom detector simulates isolated ions. It shows two possible identities for a particle. Both models have mass number 40. Both are singly charged in this simulation. The detector can also count electrons.
| Possible particle | Atomic number | Mass number | Charge |
|---|---|---|---|
| Potassium ion | 19 | 40 | +1 |
| Calcium ion | 20 | 40 | +1 |
Question 1
Calculate the neutron count for each possible ion. Use both numbers from the table.
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Question 2
What does the shared mass number establish for the two models?
- They have the same proton count.
- They have the same neutron count.
- They have the same total count of protons and neutrons.
- They are the same element.
The detector reports that the particle has 19 electrons. A student matches this count to the atomic number 19 and chooses potassium.
Question 3
Use the stated charge and electron count to identify the particle. Explain what the student overlooked.
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Question 4
Another detector reports that the neutron count equals the proton count. Use both counts to decide which candidate fits this observation.
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