An anion always
A) has a positive charge.
B) contains a group of two or more atoms with a positive charge.
C) contains a metal and a nonmetal.
D) forms covalent bonds.
E) has a negative charge.
The Correct Answer and Explanation is:
The correct answer is E) has a negative charge.
An anion is a negatively charged ion. It forms when an atom or molecule gains one or more electrons, resulting in an overall negative charge. To understand this, let’s break down the concept of ions and how anions are formed:
1. Ions and their Charges
- Ions are charged particles that form when atoms or molecules either gain or lose electrons.
- A cation is a positively charged ion, which forms when an atom loses one or more electrons (e.g., Na⁺).
- An anion, on the other hand, forms when an atom or molecule gains one or more electrons, thereby acquiring a negative charge (e.g., Cl⁻).
2. Why anions have a negative charge
- In atoms, protons (which are positively charged) and electrons (which are negatively charged) usually balance each other. However, when an atom gains extra electrons, there are more electrons than protons, making the atom negatively charged.
- For example, when a chlorine (Cl) atom gains one electron, it becomes a chloride ion (Cl⁻), which has a negative charge because the extra electron gives it one more negative charge than positive.
3. The Incorrect Options
- A) has a positive charge: This is incorrect because anions always have a negative charge, not positive.
- B) contains a group of two or more atoms with a positive charge: This describes a cation or a polyatomic ion with a positive charge, not an anion.
- C) contains a metal and a nonmetal: This is a characteristic of many salts (which involve both cations and anions), but it is not a defining feature of an anion.
- D) forms covalent bonds: While anions can form covalent bonds (for example, in molecules like H₂O), this is not exclusive to anions, and anions can also form ionic bonds.
Conclusion:
An anion always has a negative charge, which is the key characteristic distinguishing it from other types of ions.