Question 14

Chloride ions have a negative charge because they gained an electron.

Chloride ions are formed when a chlorine atom gains an extra electron, resulting in a negative charge. This process occurs because chlorine has a high electronegativity and readily accepts an electron to achieve a stable electron configuration.

A) It lost a proton.

This option is incorrect because the charge of an ion is determined by the balance of protons and electrons, not by losing protons. Chlorine does not change its proton count when it forms an ion; rather, it changes its electron count.

B) It gained a proton.

This option is also incorrect as gaining a proton would increase the positive charge of the atom, making it a cation, not an anion. Chloride ions are negatively charged due to the gain of electrons, not protons.

C) It gained an electron.

This is the correct answer. Chloride ions acquire a negative charge when a chlorine atom gains an additional electron. This gain allows the chlorine atom to achieve a stable electron configuration, characteristic of noble gases.

D) It lost an electron.

This option is incorrect because losing an electron would result in a positive charge, creating a cation instead of an anion. Chloride ions, specifically, are formed by the gain of an electron, not the loss.

Conclusion

Chloride ions are negatively charged due to the gain of an electron, which gives them a stable electron configuration. All other options fail because they misinterpret the relationship between protons and electrons in ion formation. Understanding this concept is crucial in grasping the fundamental principles of ionic charge.