Chemistry 9th Chap 5 : Topic 2 - Maryam Publications

Chemistry Chapter 5 : Topic 2

Cations and Anions

1 / 15

When a sodium atom reacts with chlorine, it loses one electron and forms a positively charged ion. Which statement best explains why sodium forms a cation instead of gaining electrons?

A) Sodium atoms already have a complete outermost shell.

B) Sodium has a higher electronegativity than chlorine.

C) Sodium atoms cannot gain electrons because their nuclei repel additional electrons.

D) Losing one electron allows sodium to achieve the stable noble gas configuration of neon.

2 / 15

An atom with the electronic configuration 2, 8, 7 is more likely to form which type of ion and why?

A) Anion, because it already has excess electrons

B) Cation, because it has nearly filled outer shell

C) Anion, because gaining one electron completes its valence shell

D) Cation, because losing seven electrons requires less energy

3 / 15

Which of the following statements correctly compares the formation of cations and anions?

A) Cations are formed by losing electrons, whereas anions are formed by gaining electrons.

B) Cations are formed by gaining electrons, whereas anions are formed by losing electrons.

C) Both cations and anions are formed by losing electrons.

D) Both cations and anions are formed by gaining electrons.

4 / 15

Magnesium forms a Mg²⁺ ion during chemical reactions. Which explanation best justifies this process?

A) Magnesium shares two electrons equally with other atoms.

B) Magnesium loses two electrons to achieve a stable noble gas configuration.

C) Magnesium gains two electrons to stabilize its nucleus.

D) Magnesium loses one proton from its nucleus.

5 / 15

A chlorine atom forms a Cl⁻ ion during reactions. Which statement correctly explains the change occurring in the atom?

A) It loses one electron and decreases its atomic size.

B) It gains one electron and completes its octet.

C) It shares electrons equally with sodium.

D) It loses one proton and forms an unstable ion.

6 / 15

Why are metals more likely to form cations, whereas non-metals tend to form anions?

A) Metals easily lose electrons due to their low ionization energy.

B) Metals have higher electron affinity than non-metals.

C) Non-metals cannot attract electrons from other atoms.

D) Metals have completely filled valence shells.

7 / 15

Which of the following changes occurs when an atom forms a cation?

A) Atomic radius increases

B) Number of neutrons decreases

C) Number of electrons increases

D) Number of electrons decreases

8 / 15

Which statement correctly compares the size of ions formed during the formation of cations and anions?

A) Cations are larger than their parent atoms, while anions are smaller.

B) Both cations and anions are smaller than their parent atoms.

C) Both cations and anions remain the same size as their parent atoms.

D) Cations are smaller than their parent atoms, while anions are larger.

9 / 15

An atom forms an ion with X ⁻² charge. Which process most likely occurred?

A) It lost two electrons.

B) It lost two protons.

C) It gained two electrons.

D) It gained two neutrons.

10 / 15

Which of the following species is an anion?

A) Al³⁺

B) Na⁺

C) Cl⁻

D) Mg²⁺

11 / 15

Which factor mainly determines whether an atom forms a cation or anion during chemical reactions?

A) Total mass of the atom

B) Number of protons in the nucleus

C) Number of electrons in the valence shell

D) Number of neutrons in the nucleus

12 / 15

Why do atoms tend to form cations or anions during chemical reactions?

A) To increase their atomic mass

B) To achieve greater nuclear stability

C) To obtain a stable noble gas electronic configuration

D) To reduce the number of protons in the nucleus

13 / 15

An atom with electronic configuration 2, 8, 2 will most likely form which ion?

A) X²⁺

B) X³⁻

C) X⁻

D) X⁺

14 / 15

Which statement best describes the difference in electron movement during the formation of cations and anions?

A) Cations are formed by electron gain, while anions are formed by electron loss.

B) Cations involve electron loss, while anions involve electron gain.

C) Both involve transfer of protons between atoms.

D) Both cations and anions involve sharing of electrons.

15 / 15

Which pair correctly represents a cation and anion respectively?

A) O²⁻, Mg²⁺

B) Cl⁻, Na⁺

C) Na⁺, Cl⁻

D) F⁻, K⁺

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