There are numerous terms involved in chemistry and physics, and today we will know about ionization energy. But before that, I would like to tell you something about the ions. Do you know? Michael Faraday was the first person to theorize the existence of ions in 1830. Through this, he mentioned the cathode and anodes. Coming back to the topic today you will learn about the ionization energy of magnesium and the minimum light required to ionize magnesium.
1. What is Meant by Ionization Energy?
The amount of minimum energy required to remove the loosely bound electrons of an isolated positive ion, molecule, or gas atom is known as the ionization energy. This term is used in both chemistry and physics. Must read How Is Energy Measured?
Here is the equation for you to understand it better.
X (g) + energy → X+ (g) + e–
In the above equation,
- X is any molecule or atom.
- X+ is the result cation ion of the process after the original atom was stripped from 1 electron.
- e– denotes the electron removed
2. How is Ionization Energy Expressed?
In physics, the ionization energy is expressed in joules (J) electron volts (eV). Whereas, in chemistry, it is the energy used to ionize a mole of molecules or atoms. It is expressed as kilocalories per mole (kcal/mol) or kilojoules per mole (kJ/mol). (See What are the Characteristics of an Element?)
3. Which Rules do Ionization Energy Follows?Image by Maurygraf from Pixabay
In the periodic table, while comparing the ionization energies, it is revealed that it follows the rules of Coulombic attraction that are as follows.
- Rule 1 – Within a given period, the ionization energy increases from left to right (in terms of row)
- Rule 2 – For a given group, the ionization energy decreases from top to bottom (in terms of column)
4. On Which Force does the Ionization Energy Depend?
Are you looking for the minimum light required to ionize magnesium? The main dependent factor of the ionization energies is the orbital energy which further depends on the effective nuclear charge and the type of orbital nuclear charge. Here the orbital energy refers to the amount of energy required to take the electron from that orbit to infinity, but it also refers to the energy that is released on the addition of an atom to that orbital from infinity. Must read How many Electrons can a Carbon Atom share?
5. What Major Factors determine Ionization Energy?Image by Openclay from Pixabay
There are different factors that have a notable influence on ionization energies. These can be nuclear charge, electron configuration, effective nuclear charge, number of electron shells, and stability. Take a look at these determinants before getting to know about the minimum light required to ionize magnesium. Here is a brief description of these factors.
- Nuclear Charge: In case the atomic number or nuclear charge is greater, the electrons will be held tighter by the nucleus. This will result in greater ionization energy which reflects rule no 1 of the table.
- Electron Configuration: All the physical and chemical characteristics of most of the elements are ascertained by determining their electronic configuration. This is applicable to most of the elements in the periodic table.
- Effective Nuclear Charge: The nucleus will hold the electrons less tightly if the magnitude of electron shielding and penetration is greater, along with smaller ionization energy, and lower effective nuclear charge of the electron.
- Stability: The stability of the electronic configuration of an atom determines its tendency to lose electrons. An atom with good stability will have lesser chances to lose electrons, and it possesses higher ionization energy.
- Number of Electron Shells: The size of an electron also determines the capability of the nucleus in holding the electrons. Like if an atom is larger the electrons will not be tightly held by the nucleus leading to small ionization energy. However, a small atom will have greater ionization energy as its nucleus is tightly holding the electrons.
6. What are Minor Determinants that Influence Energy?
Some determinants do not largely influence the ionization energies of the atoms. They are electron pairing energies, Lanthanide & actinide contraction, and Relativistic effects. Here is a description of how they influence the process and this will help you understand about the minimum light required to ionize magnesium
- Electron Pairing Energies: Subshells (the orbit around the nucleus that the electron follows) determine the level of ionization energies. When the subshells are half-filled, it means the ionization energy will be higher.
- Lanthanide & Actinide Contraction (and Scandide Contractions): Ionization energies are influenced by the shrinking of the elements. This happens due to the fact that shrinking the net charge of the nucleus is felt more strongly.
- Relativistic Effects: These effects influence the elements that are heavier as they are approaching the speed of light. These elements include those whose atomic number is more than 70. Due to this, their atomic radii are smaller, but their ionization energies are greater.
7. Why do Ionization Energies Require Light?
The importance of light or energy in the ionization of energies is due to the fact that ionization energy is correlated with the force and strength of attraction between the negatively charged valence electrons and the positively charged valence electrons. Higher ionization energy will require stronger attraction forces between the nucleus and the valence electrons, which will result in the need for more energy for removing the valence electron. (See How many valence electrons does oxygen have?)
8. What is the Ionization Energy of Magnesium?
Large jumps can be witnessed in the successive molar ionization energies of noble gases like magnesium. The formula to obtain the successive ionization energy values is as follows:
1 eV = 96.4851 kJ mol-1
The first ionization energy of magnesium with power 738 according to the calculation will be,
= 738 / 96.4851 kJ mol-1
= 7.649 eV
The second ionization energy of magnesium with power 1450 according to the following calculation will be,
= 1450 / 96.4851 kJ mol-1
= 15.029 eV
9. What is the Amount of Minimum Light Required to Ionize Magnesium?
If we talk about an atom that is initially neutral, the energy required to remove the first electron will be less than the energy required for removing the next electron. Further, the energy required by the second electron will be less than the third electron, and so on. In the case of magnesium, the minimum light required to ionize magnesium is 738 eV. (See What is the Empirical Formula of the Phosphorus Selenide?)
10. Why does the Need for Energy Increase with Every Lost Electron?Image by Nicolás Damián Visceglio from Pixabay
With every lost electron there is a considerable increase in the amount of energy required because of the following reason. After the 1st electron is lost,
- The overall charge of the atom becomes positive
- Negative forces of the electron are attracted towards the positive charge of the ion (newly formed)
Therefore, with every lost electron this positive force of the ion will be increased which will further make it harder to separate any more electrons from the atom.
So finally, you understood the ionization energy and the amount of minimum light required to ionize magnesium. Do you remember what was the ionization energy of magnesium, and how to achieve it? (See Does Magnesium Citrate Help You Sleep?)