8 original questions from New Regents. The worksheet, answer key, and browser practice are free.
Ions and Electron Counts 4 questions
Ions and Electron Counts
New Regents original practice • Name: ____________________ Date: __________ Show your work for written answers.
In these particle models, each proton contributes +1 to charge and each electron contributes −1. Neutrons have zero charge.
Question 1
A particle has 11 protons and 10 electrons. What is its charge?
- −2
- −1
- 0
- +1
Question 2
A sulfur ion has 16 protons and a charge of −2. Find its number of electrons and show the charge calculation.
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Question 3
What changes when a neutral calcium atom becomes Ca²⁺?
- It gains two protons.
- It loses two protons.
- It gains two electrons.
- It loses two electrons.
Question 4
Explain why losing an electron does not change the element or mass number of an atom.
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Particle Detector Records 4 questions
Particle Detector Records
Use the information below to answer the questions.
A model detector records proton, neutron, and electron counts. Each row describes one particle.
| Record | Protons | Neutrons | Electrons |
|---|---|---|---|
| P | 17 | 18 | 17 |
| Q | 17 | 20 | 17 |
| R | 17 | 18 | 18 |
| S | 18 | 22 | 18 |
Question 5
Which record represents an ion with a negative charge?
- P
- Q
- R
- S
Question 6
Compare P and Q. Explain how they can be isotopes of one element even though they have different mass numbers.
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Question 7
Which pair has equal electron counts but different proton counts?
- P and Q
- P and R
- Q and R
- R and S
Question 8
Use the periodic table and particle counts to write the chemical symbol with charge for R and the element symbol for neutral S.
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