Problem 4 - Campbell Biology

Question

Which statement is true of all atoms that are anions? (A) The atom has more electrons than protons. (B) The atom has more protons than electrons. (C) The atom has fewer protons than does a neutral atom of the same element. (D) The atom has more neutrons than protons.

Step-by-Step Solution

Answer

The atom has more electrons than protons. (A)

Step 1 - Understand the Definition of Anions

Anions are atoms or molecules that carry a net negative charge. This means they have gained one or more electrons.

Step 2 - Compare Electrons and Protons

Since an anion has gained electrons, it has more electrons than protons. Electrons carry a negative charge, and protons carry a positive charge.

Step 3 - Evaluate Each Statement

Look at the given statements: (A) The atom has more electrons than protons. (B) The atom has more protons than electrons. (C) The atom has fewer protons than does a neutral atom of the same element. (D) The atom has more neutrons than protons. From Step 2, we know anions have more electrons than protons, making statement (A) correct.

Step 4 - Conclusion

The true statement about all anions is that they have more electrons than protons. Therefore, the correct answer is (A).

Key Concepts

atomic structure

Atoms are the basic building blocks of matter. Each atom consists of a central nucleus surrounded by a cloud of electrons. The nucleus is home to protons and neutrons. Protons carry a positive charge, neutrons carry no charge, and electrons carry a negative charge. The atomic structure determines the properties and behavior of the atom. When these subatomic particles combine, they create the unique characteristics of each element on the periodic table.

electrons and protons

Electrons and protons are crucial in determining the charge of an atom. Protons, located in the nucleus, have a positive charge and define the element's identity through the atomic number. Electrons orbit the nucleus and have a negative charge. A neutral atom has an equal number of electrons and protons, balancing the charges. When this balance is disturbed by gaining or losing electrons, the atom becomes an ion.

ion formation

Ions are formed when atoms gain or lose electrons. If an atom loses electrons, it becomes a cation, which has a positive charge due to more protons than electrons. Conversely, when an atom gains electrons, it becomes an anion, carrying a net negative charge because it has more electrons than protons. This gain or loss of electrons impacts the atom's stability and reactivity.

charge of anions

Anions are negatively charged ions. They form when an atom gains one or more electrons. This gain increases the number of negatively charged electrons, making the anion carry a net negative charge. The defining feature of an anion is that it has more electrons than protons. In exercises, this helps to identify properties and behaviors of different atoms when they form ions. Understanding anions are key to learning about chemical reactions and bonding.