Answer:
The answer is: Metal atoms have low ionization energy, and nonmetal atoms have high electronegativity, so electrons transfer easily from the metal atom to the nonmetal atom.
Explanation:
An ionic bond is produced between metallic and non-metallic atoms, where electrons are completely transferred from one atom to another. During this process, one atom loses electrons and another one gains them, forming ions. Usually, the metal gives up its electrons forming a cation to the nonmetal element, which forms an anion.
On the other hand, the ionization energy I is the energy needed to start an electron to a gaseous atom, isolated and in a fundamental state. The electrons are attracted to the nucleus, so it is necessary to provide energy to start them. You should keep in mind that the electrons of the last layer are always lost, because they are the weakest attracted to the nucleus.
In a group, the ionization energy increases upwards because when passing from one element to the bottom, it contains one more layer of electrons. Therefore, the valence layer electrons, being further away from the nucleus, will be less attracted to it and it will cost less energy to pluck them.
In the same period, in general, it increases as you shift to the right. This is because the elements in this way have a tendency to gain electrons and therefore it will cost much more to tear them off than those on the left which, having few electrons in the last layer will cost them much less to lose them.
This can be summed up by saying that the ionization energy is minimal for alkali metals that have a single electron outside a full layer. It usually increases in each row of the periodic table, with the maximum in the noble gases that have complete layers.
Then, applied to an ionic bond, you can say that <u><em>"Metal atoms have low ionization energy, and nonmetal atoms have high electronegativity, so electrons transfer easily from the metal atom to the nonmetal atom.
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