Chapter 3: Problem 54
The first ionisation potential in electrons volts of nitrogen and oxygen atoms are respectively given as (1) \(14.61 ; 13.67\) (2) \(13.61 ; 14.6\) (3) \(13.6 ; 13.6\) (4) \(14.6 ; 14.6\)
Short Answer
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Option (1) 14.61 eV for nitrogen and 13.67 eV for oxygen.
Step by step solution
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
First Ionisation Energy
The first ionisation energy is the energy needed to remove the outermost electron from a neutral atom in its gaseous state. This value is specific for each element. To understand it better, imagine trying to pull away the electron that is closest to the nucleus of an atom. This requires energy because the electron is attracted to the positively charged nucleus.
For most elements, the first ionisation energy is a milestone value that indicates how strongly an atom holds onto its electrons. The stronger this hold, the higher the ionisation energy. Therefore, elements with high ionisation energies are less likely to lose electrons and form positive ions. Measuring ionisation energy helps chemists understand the reactivity and chemical behavior of elements.
For most elements, the first ionisation energy is a milestone value that indicates how strongly an atom holds onto its electrons. The stronger this hold, the higher the ionisation energy. Therefore, elements with high ionisation energies are less likely to lose electrons and form positive ions. Measuring ionisation energy helps chemists understand the reactivity and chemical behavior of elements.
Nitrogen and Oxygen Ionisation
When comparing the ionisation energies of nitrogen and oxygen, there is something interesting to note. Although oxygen has one more proton in its nucleus than nitrogen, its first ionisation energy is actually slightly lower. The first ionisation energy for nitrogen is around 14.53 eV, and for oxygen, it is about 13.62 eV.
This can be explained by understanding electron configuration and electron-electron repulsion. Nitrogen has a half-filled p-orbital which is relatively stable. Removing an electron from this stable configuration requires more energy. On the other hand, oxygen has one more electron paired in a p-orbital, which introduces some repulsion between the paired electrons. This makes it slightly easier to remove one of these electrons, resulting in a lower ionisation energy compared to nitrogen.
This can be explained by understanding electron configuration and electron-electron repulsion. Nitrogen has a half-filled p-orbital which is relatively stable. Removing an electron from this stable configuration requires more energy. On the other hand, oxygen has one more electron paired in a p-orbital, which introduces some repulsion between the paired electrons. This makes it slightly easier to remove one of these electrons, resulting in a lower ionisation energy compared to nitrogen.
Electron Volts (eV)
Ionisation energy is often measured in electron volts (eV). An electron volt is a unit of energy that is equal to the work done on an electron in moving it through an electric potential difference of one volt. In simpler terms, 1 eV is the amount of kinetic energy gained or lost by an electron as it moves between two points with a 1 volt difference.
The usage of eV in ionisation energy is prevalent because it provides a practical way of expressing tiny amounts of energy, like the energy changes involved in atomic and subatomic processes. When dealing with atoms and the changes they undergo, using electron volts makes calculations and comparisons more intuitive.
The usage of eV in ionisation energy is prevalent because it provides a practical way of expressing tiny amounts of energy, like the energy changes involved in atomic and subatomic processes. When dealing with atoms and the changes they undergo, using electron volts makes calculations and comparisons more intuitive.
Comparative Analysis of Ionisation Energy
Comparing ionisation energies across different elements offers insights into their chemical properties. For example, elements with low ionisation energies tend to lose electrons easily and form cations. These elements are often metals. Conversely, elements with high ionisation energies are less likely to lose electrons, making them nonmetals or noble gases.
In the context of nitrogen and oxygen, we observe that although oxygen has more electrons and a stronger positive charge in its nucleus, its first ionisation energy is lower than that of nitrogen. This counter-intuitive result is due to electron configurations and the repulsion forces among electrons.
Understanding and comparing ionisation energies helps predict how elements will interact in chemical reactions. It is a critical concept for mastering topics in chemistry and understanding the periodic trends in the periodic table.
In the context of nitrogen and oxygen, we observe that although oxygen has more electrons and a stronger positive charge in its nucleus, its first ionisation energy is lower than that of nitrogen. This counter-intuitive result is due to electron configurations and the repulsion forces among electrons.
Understanding and comparing ionisation energies helps predict how elements will interact in chemical reactions. It is a critical concept for mastering topics in chemistry and understanding the periodic trends in the periodic table.
