Doc: Metals, Non-Metals and Metalloids Class 11 Notes | EduRev

Chemistry Class 11

JEE : Doc: Metals, Non-Metals and Metalloids Class 11 Notes | EduRev

The document Doc: Metals, Non-Metals and Metalloids Class 11 Notes | EduRev is a part of the JEE Course Chemistry Class 11.
All you need of JEE at this link: JEE

 METALS AND NON-METALS

  • The metals are characterised by their nature of readily giving up the electron and from shinning lusture. Metals comprises more than 75% of all known elements and appear on the left hand side of the periodic table. Metals are usually solids at room temperature (except mercury). They have high melting and boiling points and are good conductors of heat and electricity. Oxides of metals are basic in nature. (Some metals in their higher oxidation state form acid oxides e.g. CrO3)
  • Non-metals do not lose electrons but take up electrons to form corresponding anions. Non-metals are located at the top right hand side of the periodic table. Non-metals are usually solids or gases at room temperature with low melting and boiling points. They are poor conductors of heat and electricity.
  • Oxides of non-metals are acidic in nature.

METALLOIDS (SEMI METALS)

  • It is very much clear from the periodic table that non-metallic character increases as we move from left to right across a row. It has been found that some elements lying at the border of metallic and non-metallic behaviour, possess the properties that are characteristic of both metals and non-metals.
  • These elements are called semi metals or metalloids. 
  • The metalloids comprise of the elements B, Si, Ge, As, Sb and Te.
  • Oxides of metalloids are generally amphoteric in nature. 

TYPICAL ELEMENTS :

  • Third period elements are called as typical elements. These include Na, Mg, AI, Si, P, S, CI.
  • The properties of all the elements belonging to a particular group resemble the properties of the corresponding typical element of that group. For example, the general properties of alkali metals (IA) can be predicted from the properties of Na, not Li, the first member of the group.
  • The properties of the elements of second period differ in the many respect belonging to the same group due to the smaller atomic size and absence of vacant d-orbitals.

DIAGONAL RELATIONSHIP :

Some elements of certain groups of 2nd period resemble much in properties with the elements of third period of next group i.e. elements of second and third period are diagonally related in properties. This phenomenon is known as diagonal relationship.

 Doc: Metals, Non-Metals and Metalloids Class 11 Notes | EduRev 

Diagonal relationship arises because of

(i) similar size of atom and ions
Li = 1.23 Å & Mg = 1.36 Å; Li+ = 0.60 Å & Mg2+ = 0.65 Å

(ii) similar electropositive characters

(iii) similar polarising powers (charge to radius ratio)

(iv) similarity in electronegativity values
(Li = 1.0 & Mg = 1.2; Be = 1.5 &AI = 1.5)


Similarities between properties of Li and Mg are as follows:
(a) Li and Mg both reacts directly with nitrogen to form lithium nitride (Li3N) and magnesium nitride (Mg3N2) whereas other alkali metals of I A group does not form nitride.
(b) Fluoride, carbonate and phosphate of Li and Mg are insoluble in water whereas these compounds of other alkali metals are soluble.
(c) Li and Mg both are hard metals, whereas other metals of I A group are soft.
(d) LiOH and Mg(OH)2 both are weak bases, whereas hydroxides of other elements of IA group are strong base.
(f) Metallic bond in Li and Mg both are strong compare to other alkali metals.
(g) Their melting and boiling points are high.
(h) By thermal disintegration of LiNO3 and Mg (NO3)2 ; Li2O and MgO is obtained respectively.
(I) Thermal stability of Li2CO3 and Mg CO3 is very less compare to other alkali metals and they liberates COgas easily.


Similarly, Be shows similarity to Al of IIIA group compare to other elements of IIA group which are as follows:
(a) These both elements do not provide colour to Bunsen burner.
(b) They both are comparatively stable in air.
(c) Both are insoluble in NH3, therefore, do not form blue coloured solution.
(d) There is no tendency of making peroxide and superoxide in them.
(e) Reducing power is very less due to low value of standard electrode potential in the form of oxidation potential.
(f) Be and AI both forms halogen bridge halides.


Doc: Metals, Non-Metals and Metalloids Class 11 Notes | EduRev

Offer running on EduRev: Apply code STAYHOME200 to get INR 200 off on our premium plan EduRev Infinity!

Related Searches

shortcuts and tricks

,

Important questions

,

mock tests for examination

,

Semester Notes

,

Previous Year Questions with Solutions

,

video lectures

,

ppt

,

practice quizzes

,

Sample Paper

,

pdf

,

Objective type Questions

,

past year papers

,

Non-Metals and Metalloids Class 11 Notes | EduRev

,

Viva Questions

,

Doc: Metals

,

MCQs

,

Non-Metals and Metalloids Class 11 Notes | EduRev

,

Exam

,

study material

,

Free

,

Doc: Metals

,

Doc: Metals

,

Summary

,

Non-Metals and Metalloids Class 11 Notes | EduRev

,

Extra Questions

;