mention the properties of group13 and group18 elements in detail.
Answers
Answer:
Physical Properties of Group 13 Elements
In this section, we will look at the physical properties of the boron family.
Indium has a lesser nuclear radius than Thallium. This is because of the lanthanide compression.
As we move down the group, +1 oxidation state turns out to be steadier than +3 states. This is mainly because of the inert pair impact.
Boron has a high melting point. This is because of the icosahedral structure. In the boron family, gallium has the lowest melting point.
All the elements of this family blaze in oxygen at high temperatures framing M2O3.
Aluminium is amphoteric. It means that the metal disintegrates in weakened mineral acids and in sodium hydroxide (aqueous).
As we move down the group, the acidic nature of hydroxides reduces.
Boric acid is an extremely delicate monobasic acid.
Chemical Properties of Group 13 Elements
Dissociation of the group 13 elements requires a lot of energy. This is because the compounds formed by the Group 13 elements with oxygen are inert thermodynamically.
Boron acts as a non-metal chemically. However, the rest of the elements show metallic properties. Why does this happen? A large portion of the irregularities seen in the properties of the group 13 elements is attributed to the expansion in Zeff(Effective Nuclear Charge). This emerges from the weakened protection of the atomic charge by the filled (n − 1) d10 and (n − 2) f14 subshells.
Rather than shaping a metallic grid with delocalized valence electrons, boron frames special aggregates that consist of multicenter bonds. This includes metal borides, in which boron attaches to other boron iotas. This arrangement creates three-dimensional systems or bunches with consistent geometric structures.
All the neutral compounds of the group 13 elements are electron lacking and act like Lewis acids. The trivalent halides of the heavier elements shape halogen-connected dimers that consist of electron-match bonds, as opposed to the delocalized electron-lacking bonds typical for diborane.
Their oxides break down in weakened acids, in spite of the fact that the oxides of aluminium and gallium are amphoteric. The group 13 elements never react with hydrogen because the valency of hydrogen is one and that of the boron family is three. The trihalides of group 13 elements are strong Lewis acids because they have the tendency to form compounds with electron-pair donors, the Lewis bases.
GROUP 18
Physical Properties
Because of their stable nature, we find these elements as monatomic gases in a free state.
They are colourless, tasteless and odourless gases. The particles of these elements have weak Van der Waals forces. This force increases on moving down the group. This is due to an expansion in the polarising capacity of the molecules.
They exhibit low melting and boiling points. We can attribute this to the weak Van der Waals forces. The melting and boiling points increase as we move down the group.
We can condense these elements at extremely low temperatures. As the size of the atoms increases down the group, the ease of liquefaction also increases.
Chemical Properties
These elements are chemically latent because of their stable electronic configuration.
Group 18 elements have high positive electron gain enthalpy and high ionization enthalpy.
In 1962, Neil Bartlett anticipated that xenon ought to react with platinum hexafluoride. He was the first to set up a compound of xenon, called xenon hexafluoroplatinate(V). Later, many compounds of xenon were integrated, including fluorides, oxyfluorides, and oxides.
Xe + PtF6 → Xe[PtF6]
Xenon Platinum Hexafluoride Xenon Hexafluoroplatinate(V)
The chemical movement of group eighteen elements increments with a diminishment in the ionization enthalpy on moving down the group.
The ionization enthalpies of helium, argon, and neon are too high for them to shape compounds.
Krypton only forms krypton difluoride, since its ionization enthalpy is marginally higher than that of xenon.
Although radon has less ionization enthalpy than xenon, it shapes just a few compounds like radon difluoride, and a few complexes, since radon has no steady isotopes. In any case, xenon shapes an especially more prominent number of compounds.