Cations and Anions: Questions on Properties and Identification

Questions on Cations and Anions

 Understanding cations and anions is fundamental to chemistry because ions play a central role in chemical bonding, reactions, and compound formation. This material is designed to help students, educators, and exam candidates strengthen their understanding of positively and negatively charged ions through practice questions that reinforce key concepts used in general chemistry and related scientific fields. As a Science Teacher and Education Specialist, I develop educational resources that connect scientific concepts with effective learning strategies. 

Cations and anions are electrically charged particles formed when atoms gain or lose electrons. Cations carry positive charges, while anions carry negative charges. These ions are essential to understanding ionic bonding, chemical reactions, and the formation of compounds. Mastering the properties and identification of cations and anions provides students with a strong foundation for general chemistry, analytical chemistry, and many applications in environmental science and industry. Practice questions help reinforce these concepts and improve problem-solving skills.

Multiple-Choice Questions: Cations and Anions


Basic Concepts

    1. What is a cation?

A) A neutral atom

B) An atom that gains electrons

C) An atom that loses electrons

D) A molecule with a positive and negative side

E) A negatively charged ion

    2. What is an anion?

A) A positively charged ion

B) A neutral particle

C) A molecule with polar bonds

D) A negatively charged ion

E) An atom that loses protons

    3. Cations are formed when an atom:

A) Gains electrons

B) Loses protons

C) Loses electrons

D) Gains neutrons

E) Shares electrons

    4. Which of the following is a cation?

A) Cl⁻

B) O²⁻

C) Na⁺

D) N³⁻

E) F⁻

    5. Which of the following is an anion?

A) Ca²⁺

B) Al³⁺

C) Li⁺

D) S²⁻

E) Mg²⁺


🔹 Identifying Ions

    6. The charge on a calcium ion (Ca) is:

A) +1

B) +2

C) -1

D) -2

E) 0

    7. Which of the following elements commonly forms a -1 anion?

A) Sodium

B) Magnesium

C) Chlorine

D) Aluminum

E) Calcium

    8. What is the charge of an oxide ion?

A) -1

B) +2

C) -2

D) +1

E) 0

    9. Which ion is formed by nitrogen?

A) N⁻

B) N⁺

C) N²⁺

D) N³⁻

E) N²⁻

    10. Which of these ions is NOT correctly matched to its charge?

A) Na⁺ — +1

B) Cl⁻ — -1

C) O²⁻ — -2

D) Mg²⁺ — +1

E) Al³⁺ — +3


🔹 Periodic Table Patterns

    11. Which group in the periodic table forms cations most easily?

A) Group 1 (alkali metals)

B) Group 17 (halogens)

C) Group 18 (noble gases)

D) Group 16 (oxygen group)

E) Group 14 (carbon group)

    12. Halogens usually form ions with what charge?

A) +2

B) -1

C) +1

D) -2

E) 0

    13. Metals generally form:

A) Anions

B) Covalent bonds only

C) Cations

D) Hydrogen bonds

E) Neutral atoms

    14. Nonmetals tend to form:

A) Cations

B) No ions at all

C) Ionic solids

D) Anions

E) Positive molecules

    15. Which of the following elements is most likely to form a +3 cation?

A) Sodium

B) Calcium

C) Chlorine

D) Aluminum

E) Oxygen


🔹 Naming and Notation

    16. Which of these ions is written correctly?

A) Na⁻

B) Cl⁺

C) Ca⁺

D) Fe²⁺

E) O⁺

    17. How is a potassium ion written?

A) K

B) K⁻

C) K⁺

D) K²⁻

E) K²⁺

    18. How is a fluoride ion written?

A) F⁺

B) F

C) F⁻

D) F₂⁻

E) F₃⁻

    19. What is the name of the ion O²⁻?

A) Oxygen ion

B) Oxide ion

C) Dioxide ion

D) Oxygenide ion

E) Oxyion

    20. The ion Cl⁻ is called:

A) Chlorate

B) Chloride

C) Chlorine ion

D) Hypochlorite

E) Chloronium


🔹 Ionic Compounds and Behavior

    21. In ionic compounds, cations are typically from:

A) Nonmetals

B) Metalloids

C) Metals

D) Gases

E) Organic molecules

    22. In ionic compounds, anions are usually:

A) Metals

B) Noble gases

C) Positive ions

D) Nonmetals

E) Water molecules

    23. Which of the following compounds contains both a cation and an anion?

A) NaCl

B) O₂

C) H₂O

D) CH₄

E) CO₂

    24. Which of these substances is formed by ionic bonding?

A) Cl₂

B) CO

C) NaBr

D) HCl

E) NH₃

    25. What happens to the size of an atom when it becomes a cation?

A) Increases

B) Stays the same

C) Doubles

D) Decreases

E) Becomes unstable


🔹 Advanced Application

    26. A Cu²⁺ ion has:

A) Gained 2 electrons

B) Lost 2 electrons

C) Gained 2 protons

D) Lost 2 protons

E) Gained 2 neutrons

    27. Which is the correct name for Mg²⁺?

A) Magnesium ion

B) Manganese ion

C) Magnesium(II)

D) Magnesiumite

E) Magneside

    28. Which ion is common in table salt?

A) K⁺

B) Na⁺

C) Cl⁺

D) Mg²⁺

E) Br⁻

    29. Which of the following ions is polyatomic?

A) Na⁺

B) O²⁻

C) SO₄²⁻

D) K⁺

E) F⁻

    30. What is the overall charge of a neutral ionic compound?

A) +1

B) -1

C) 0

D) +2

E) Depends on the ions

 

  Answers with Explanations

    1. C – A cation forms when an atom loses electrons and becomes positively charged.

    2. D – An anion is negatively charged due to gaining electrons.

    3. C – Loss of electrons forms a positive ion (cation).

    4. C – Na⁺ is a positively charged sodium ion (cation).

    5. D – S²⁻ is a sulfur ion that has gained 2 electrons.

    6. B – Calcium forms Ca²⁺ by losing 2 electrons.

    7. C – Chlorine (Cl) typically forms Cl⁻.

    8. C – Oxide (O²⁻) is formed when oxygen gains 2 electrons.

    9. D – Nitrogen forms N³⁻ by gaining 3 electrons.

    10. D – Mg²⁺ is +2, not +1.

    11. A – Group 1 elements (alkali metals) lose 1 electron to form cations.

    12. B – Halogens form -1 anions.

    13. C – Metals tend to lose electrons → cations.

    14. D – Nonmetals gain electrons → anions.

    15. D – Aluminum typically forms Al³⁺.

    16. D – Fe²⁺ is correct (iron(II)).

    17. C – Potassium ion is K⁺.

    18. C – Fluoride ion is F⁻.

    19. B – O²⁻ is called oxide.

    20. B – Cl⁻ is the chloride ion.

    21. C – Cations are usually metal atoms.

    22. D – Anions are nonmetal atoms.

    23. A – Na⁺ + Cl⁻ = NaCl, an ionic compound.

    24. C – NaBr is an ionic compound.

    25. D – Cations are smaller than their neutral atoms.

    26. B – Cu²⁺ has lost 2 electrons.

    27. A – Mg²⁺ is the magnesium ion.

    28. B – Table salt = NaCl (Na⁺ and Cl⁻).

    29. C – SO₄²⁻ is a polyatomic ion (sulfate).

    30. C – Ionic compounds are neutral overall (total charge = 0).

Cations and Anions: Questions on Properties and Identification

Practical Classroom Applications

• Explain Ion Formation

Demonstrate how atoms gain or lose electrons to become positively or negatively charged ions.

• Use the Periodic Table

Teach students how element groups can help predict common ionic charges.

• Compare Cations and Anions

Create charts showing differences in charge, electron behavior, and examples of common ions.

• Practice Compound Formation

Combine cations and anions to form ionic compounds and balance charges.

• Explore Real-World Applications

Discuss the role of ions in batteries, electrolytes, water treatment, and biological systems.

• Reinforce Oxidation States

Introduce oxidation numbers and their importance in chemical reactions.

• Strengthen Scientific Vocabulary

Develop familiarity with chemistry terminology used in laboratories and advanced science courses.

• Prepare for Exams

Use the questions for classroom review, AP Chemistry, high school chemistry, and introductory college chemistry courses.

compartilhe compartilhe

Share Social !


Ronaldo Silva: Professor and Specialist in Science Education from University Federal FLuminense/RJ, with over 25 years of teaching experience..

 
About | Terms of Use | Cookies Polices | Privacy

Questions: Science, Math and Chemistry

John 3:16 For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.