Question

Atom A has valence electrons that are lower in energy than the valence electrons of Atom B. Which atom has the higher ionization energy? Explain.

Short answer

Atom A has the higher ionization energy because its valence electrons are lower in energy (closer to the nucleus) compared to Atom B's valence electrons. This means it is more difficult to remove the valence electrons of Atom A, resulting in a higher ionization energy.

Step-by-step solution

Understand Ionization Energy

Ionization energy is the amount of energy required to remove an electron from an atom. In general, the greater the distance between an electron and the nucleus, the easier it is to remove the electron and the lower the ionization energy. Conversely, the closer an electron is to the nucleus, the harder it is to remove the electron and the higher the ionization energy.

Compare Valence Electrons

We are given that Atom A's valence electrons are lower in energy than Atom B's valence electrons. This means that the valence electrons in Atom A are closer to the nucleus and experience a stronger attraction to the positive protons in the nucleus.

Relate Valence Electron Energy to Ionization Energy

Since Atom A's valence electrons are closer to the nucleus and have lower energy, it is more difficult to remove these electrons, which means Atom A has a higher ionization energy. On the other hand, the valence electrons of Atom B are farther from the nucleus and have higher energy, making it easier to remove them. Thus, Atom B has a lower ionization energy.

Answer the Question

In conclusion, Atom A has the higher ionization energy because its valence electrons are lower in energy (closer to the nucleus) compared to Atom B's valence electrons.

Key concepts

Valence Electrons

Valence electrons are the outermost electrons of an atom. These electrons reside in the atom's highest energy level. They are significant because they determine how an atom interacts with others. The number of valence electrons can dictate how easily an atom can form bonds. For instance, an atom with a full outer shell is typically more stable and less reactive. However, atoms with incomplete valence shells tend to be more reactive. They are more likely to gain, lose, or share electrons to achieve a stable configuration. The energy level of these valence electrons directly influences their reactivity. If the valence electrons are lower in energy, they are more tightly bound to the nucleus and less likely to participate in chemical reactions.

Electron-Nucleus Attraction

Electron-nucleus attraction is the force that holds electrons in orbit around the nucleus. This attraction is due to the electromagnetic force—where opposite charges attract. Electrons, which are negatively charged, are drawn toward the positively charged protons in the nucleus. The strength of this attraction depends on several factors:

• Distance between the electron and the nucleus: Closer electrons experience stronger attraction.
• Charge of the nucleus: More protons result in a stronger positive charge, increasing attraction.
• Energy level of the electron: Lower energy electrons are usually closer to the nucleus and more strongly attracted.

A strong electron-nucleus attraction means that more energy will be required to remove an electron, indicating a higher ionization energy.

Atomic Structure

Atoms are the basic units of matter, made up of three main subatomic particles: protons, neutrons, and electrons. Protons and neutrons reside in the nucleus at the center of the atom, while electrons orbit around the nucleus. The number of protons, known as the atomic number, defines the identity of the element. The structure of an atom is analogous to a solar system, where the nucleus represents the sun and electrons represent planets orbiting around it. Electrons are arranged in energy levels or shells, with valence electrons located in the outermost shell. An atom's behavior and properties in chemical reactions largely depend on this configuration. When valence electrons are involved, understanding the atomic structure helps explain why certain atoms have higher ionization energies based on how tightly their electrons are held by the nucleus.