Three atoms have the following electron configurations: (a) 1s2 2s2 2p6 3s2 3p3 (b) 1s2 2s2 2p6 3s2 3p6 (c) 1s2 2s2 2p6 3s2 3p6 4s2 Which of the three has the largest Ei2? Which has the smallest Ei7?

Verified step by step guidance

1. Identify the elements based on their electron configurations: (a) 1s2 2s2 2p6 3s2 3p3 corresponds to Phosphorus (P), (b) 1s2 2s2 2p6 3s2 3p6 corresponds to Argon (Ar), and (c) 1s2 2s2 2p6 3s2 3p6 4s2 corresponds to Calcium (Ca).
2. Understand the concept of Ionization Energy (Ei): It is the energy required to remove an electron from a gaseous atom or ion. The first ionization energy (Ei1) is the energy to remove the first electron, Ei2 is for the second electron, and so on.
3. Consider the general trend in ionization energies: Ionization energy generally increases across a period (from left to right) and decreases down a group (from top to bottom) in the periodic table.
4. Analyze the electron configurations and their stability: Elements with a completely filled or half-filled p-orbital (like Argon with a filled 3p orbital) are generally more stable, requiring more energy to remove electrons, especially the initial ones.
5. Compare the stability and electron configurations to estimate the largest Ei2 and smallest Ei7: For Ei2, consider the stability after the first electron has been removed. For Ei7, consider how many electrons need to be removed and how this affects the stability of the resulting ion.

Key Concepts

Ionization Energy (Ei)

Ionization energy is the energy required to remove an electron from an atom or ion in its gaseous state. It is a critical concept in understanding how easily an atom can lose electrons, which is influenced by factors such as atomic size, nuclear charge, and electron shielding. Generally, ionization energy increases across a period and decreases down a group in the periodic table.

Electron Configuration

Electron configuration describes the distribution of electrons in an atom's orbitals. It provides insight into the atom's chemical properties and reactivity. The configurations given in the question indicate the number of electrons in each energy level and sublevel, which directly affects the atom's ionization energies and how tightly electrons are held by the nucleus.

Trends in Ionization Energy

Trends in ionization energy refer to the predictable changes in ionization energy values across periods and groups in the periodic table. As you move from left to right across a period, ionization energy generally increases due to increased nuclear charge and decreased atomic radius. Conversely, as you move down a group, ionization energy decreases because of increased electron shielding and greater distance from the nucleus, making it easier to remove electrons.