Question

Write equations that show the processes that describe the first, second, and third ionization energies of a chlorine atom. Which process would require the least amount of energy?

Short answer

The first, second, and third ionization energies of a chlorine atom can be represented by the following equations: 1. First ionization energy: \(Cl + e^{-} \rightarrow Cl^{+}\) 2. Second ionization energy: \(Cl^{+} + e^{-} \rightarrow Cl^{2+}\) 3. Third ionization energy: \(Cl^{2+} + e^{-} \rightarrow Cl^{3+}\) The process that requires the least amount of energy is the first ionization process \(Cl + e^{-} \rightarrow Cl^{+}\), as ionization energy typically increases with the charge of the ion.

Step-by-step solution

Write the first ionization energy equation

The first ionization energy corresponds to the removal of one electron from a neutral chlorine atom. The general formula for ionization energy is: \[X^{n+} + e^{-} \rightarrow X^{(n+1)+}\] For the first ionization energy of chlorine, the equation is: \[Cl + e^{-} \rightarrow Cl^{+}\]

Write the second ionization energy equation

The second ionization energy corresponds to the removal of another electron from the ion formed after the first ionization. For a chlorine ion with a charge of +1, the equation is: \[Cl^{+} + e^{-} \rightarrow Cl^{2+}\]

Write the third ionization energy equation

The third ionization energy corresponds to the removal of yet another electron, this time from the ion formed after the second ionization. For a chlorine ion with a charge of +2, the equation is: \[Cl^{2+} + e^{-} \rightarrow Cl^{3+}\]

Determine the process requiring the least energy

In general, the ionization energy increases as the charge of the ion increases since the attraction between the positively charged nucleus and the negatively charged electrons also increases. Therefore, the process requiring the least amount of energy is the first ionization process: \[Cl + e^{-} \rightarrow Cl^{+}\]

Key concepts

Chlorine Atom

The chlorine atom is a chemical element, number 17 on the periodic table, with the symbol Cl. It is found in the halogen group. In its atomic state, chlorine has 17 electrons. These electrons are arranged in various energy levels around the nucleus.
The outermost shell contains 7 electrons, making chlorine eager to gain an additional electron to achieve a stable electron arrangement. This electronic structure makes chlorine very reactive and a common participant in many types of chemical reactions.
Understanding chlorine's electronic configuration helps explain its behavior during ionization. When an electron is removed from a chlorine atom, it requires energy, known as ionization energy. The ability of chlorine to form ions is foundational to many chemical processes. Exploring chlorine's initial configuration helps us understand why it requires different amounts of energy to remove electrons.

Electron Removal

Electron removal refers to the process of detaching one or more electrons from an atom or ion, usually requiring energy. This is a significant chemical process because it changes the charge of the atom.
In the case of chlorine, the first electron removal involves taking an electron from the neutral atom, forming a positively charged ion (Cl⁺).
Atoms are neutral when they have an equal number of protons and electrons. When an electron is removed, the balance is disrupted, resulting in a net positive charge. This charge change explains why different ionization steps require varying amounts of energy. Each subsequent electron removal from chlorine after the first requires substantially more energy due to the increased positive charge of the nucleus attracting the remaining electrons more strongly.

Chemical Equation

Chemical equations are symbolic ways of representing chemical reactions. They show the reactants on the left side and the products on the right side, separated by an arrow indicating the direction of the reaction.
For ionization, these equations show the initial atom or ion and the resultant ion after electron removal, along with the electron itself (e^-).
For example, the first ionization energy equation for chlorine is written as:

• \[ Cl + e^{-} \rightarrow Cl^{+} \]

This equation illustrates the transition of a neutral chlorine atom to a singly charged ion. Similarly, equations for subsequent ionizations show the further removal of electrons and the formation of more highly charged ions. Writing these equations helps visualize and understand the process of ionization step by step.

Ionization Process

The ionization process is a fundamental concept in chemistry, concerned with the removal of electrons from an atom or molecule. This process is impacted by factors like the nuclear charge and the distance of electrons from the nucleus.
In chlorine, the first ionization energy involves removing one electron from the neutral atom, which is the process requiring the least energy.
The equations for the successive ionizations of chlorine are:

• First Ionization: \[ Cl + e^{-} \rightarrow Cl^{+} \]
• Second Ionization: \[ Cl^{+} + e^{-} \rightarrow Cl^{2+} \]
• Third Ionization: \[ Cl^{2+} + e^{-} \rightarrow Cl^{3+} \]

The first ionization is the easiest because it involves removing an electron from a neutral atom. As the positive charge increases with subsequent ionizations, more energy is required. This illustrates why the first ionization is the least energy-intensive process compared to later stages.