* ѕoмe вaѕιc concepтѕ * #chemistry What is the difference betw | IIT JEE MAIN
* ѕoмe вaѕιc concepтѕ *
#chemistry
What is the difference between s-block and p-block elements?
ᑕOᑎᑕƐᑭTS :
They are grouped as s-block or p-block according to the position of valence electrons in orbitals. The main difference between s and p block elements is that the valence electrons of the s-block elements are in the s-orbital whereas the valence electrons of the p-block elements are in the p-orbital.
What behaviour of the third period of p-block elements?
ᑕOᑎᑕƐᑭTS :
The third period elements of p-groups with the electronic configuration 3s2 ,3pn have the vacant 3d orbitals lying between the 3p and the 4s levels of energy. Using these d-orbitals the third period elements can expand their co-valence above four.
How does the presence of d-orbitals affect the properties of heavier metals?
ᑕOᑎᑕƐᑭTS :
The presence of d-orbitals influences the chemistry of the heavier elements in these ways:
1. The combined effect of size and availability of d orbitals considerably influences the ability of these elements to form ππ bonds.
2. The first member of a group differs from the heavier members in its ability to form pπ−pπpπ-pπ multiple bonds to itself.
Why heavier metals show reluctance for pπ-pπ bonding ?
ᑕOᑎᑕƐᑭTS :
The heavier elements do form ππ bond but this involves d orbitals (dπ−pπ or dπ−dπ)(dπ-pπ or dπ-dπ) type bonding as the d orbitals are of higher energy than the p orbitals, they contribute less to the overall stability of molecules than does pπ−pπpπ-pπ bonding of the second row elements.
What are the properties of the Boron group of elements?
ᑕOᑎᑕƐᑭTS :
1. Boron is a typical non-metal, aluminium is a metal but shows many chemical similarities to boron, and gallium, indium, thallium and nihonium are almost exclusively metallic in character.
2. Boron is a fairly rare element, mainly occurs as orthoboric acid, (H3BO3), borax, Na2B4O7·10H2O, and kernite, Na2B4O7·4H2O
3. The abundance of boron in earth crust is less than 0.0001% by mass.
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