Future Experts come here and share their knowledge base and concepts with each other. Every article submitted is reviewed by experts. Nickels are awarded to articles in terms of authenticity, relevance, clarity and presentation.
Why is mercury a liquid at STP? Mercury is puzzling in several ways. It's a liquid at room temperature and pressure, but all of its neighbors on the periodic table are solids. Mercury is much less reactive than cadmium or zinc, and it is difficult to oxidize. It has poorer thermal and electrical conductivity than its neighbors. Being a liquid, its melting and boiling points are much lower than its neighbors. Why are most metals solids? The ionization energy of metallic elements is very low. They easily lose their valence electrons, and share them with surrounding metal atoms. This delocalized 'soup' of valence electrons binds together the me
more ...
submitted by madmax (199 m) on 21 Feb 2008 20:45:00 IST (11 comments 174 views)
PLZ DON'T THINK THESE ARE WRITTEN BEFORE ONLY 1-2 PTS CAN MATCH 1) Largest atomic size - cesium 2)lowest atomic size - H 3)Largest Anion - At - 4)smallest anion - F - 5)Lowest electronegativity - Cs 6)Lowest electron affinity - noble gases 7)Metals having highest b.pt and m.pt. = mercury and tungsten 8)Non metal having highest m.pt and b.pt = Helium 9)Most reactive solid ekement - Li 10)Most reactive liquid element - Cs 11)Most reactive gaseous element - Flourine 12)Most s
more ...
submitted by chimanshu_007 (11504 m) on 10 May 2007 14:36:57 IST (13 comments 636 views)
Some points of group 14..... 1) Dry ice (solid CO2) is a molecular solid (vander waal's solid) 2)Anthracite is the purest form of coal while lamp black is the softest 3)Tin is the element having maximum no. of isotopes 4)graphitic acid (C11H4O5) is obtained by oxdn. of graphite with conc. HNO3 5) water gas is also known as blue gas bcoz it burns with a blue flame 6)Quartz is the purest and very common variety of silica 7)Tin is nt attacked by organic acids and used in tinning of utensils
more ...
submitted by chimanshu_007 (11504 m) on 22 May 2007 15:30:53 IST (12 comments 633 views)
IF A COMPOUND GIVES RED COLOUR WITH NH4(SCN) THEN IT MUST CONTAIN Fe(3+) IF IT IS BLUE,IT MUST BE Co(2+) &IF IT IS BLACK IT MUST BE Cu(2+). IF A GAS TURNS PYROGALLOL TO BLACK IT MUST BE OXYGEN ON ADDING KI IF ORANGE OR RED PPT IS FORMED IT AND DISAPPEARS ON ADDING EXCESS KI ,IT MUST BE Hg2+ IF X TURNS aqHYPO SOLN TO WHITE PPT AND TURNS BLACK ON STANDING THEN IT MUST BE Ag+ IF SULPHIDE IS INSOLUBLE IN YELLOW AMMONIUM SULPHIDE(YAS) IT MUST BE COPPER GROUP NaOH AND Fe(OH)3 ARE SEP. BY ADDING WATER TO MIXTURE. Ni(OH)2 &Fe(OH)3 CAN BE SEPARATED BY ADDING NH4OH WHEN FIRST DISSOLVES BUT LATER DOES NOT. MnS & CoS ARE SEPARATED BY ADDI
more ...
submitted by beethoven (151 m) on 5 Aug 2007 21:43:36 IST (4 comments 186 views)
some basic points in oxygen family 1)the acidic nature of the hydrides is quite reversed of wat is expected, bond is most polar in H2O , so it is least acidic order is H2O < H2S < H2Se < H2Te 2)Only S , Se , Te in grp 16 shows catenation property (all 8 membered rings), Oxygen exist is diatomic , Po is monoatomic 3)H2O has the highest M Pt. and B Pt., this is due to extensive H-Bonding (though is contradictory by vander waal's forces) 4)FRrom 273 to 277K densityof water increases i.e it contracts , bt after 277K , it starts expanding with increase n temp so H20 has max density at 2
more ...
submitted by chimanshu_007 (11504 m) on 13 Jun 2007 00:42:08 IST (8 comments 522 views)
some imp. pts about d and f block elements 1)all transition elements are d block elements but all d block are nt transition elements 2)lightest transition metal is Sc (denstity 3.1 g / cm^3) heaviest transition metal is osmium 3)the reactivity of transition metals decreases with increase in atomic number 4)All elements of 3d series are good reducing agaents except copper 5)Cu+ with d10 electronic configuration shld be stable bt d9 is more stable due to increased hyb. 6)Mo is used in X ray tubes , Ta in analytic weights instru
more ...
submitted by chimanshu_007 (11504 m) on 23 May 2007 13:19:55 IST (3 comments 281 views)
some pts of grp 13 elements :) 1) In grp 13 , gallium has lowest melting point 2)Aluminothermy used for on the spot welding of large iron structures is based on fact that Al has greater affinity fr oxygen than iron 3)Boron doesnot react with HCl to form chlorides 4)Al is the metal protected by its own oxide 5)Thalium in group 13 doesnot show group valency in the compounds 6)BCl3 and AlCI3 are lewis acids but AlCI3 is more stronger than BCI3 7)AlCl3 exist as a dimer bcoz high co-ordination can be achieved by Al 8)Inorganic
more ...
submitted by chimanshu_007 (11504 m) on 21 May 2007 20:04:22 IST (7 comments 310 views)
HI EVERYONE ????.WHENEVER I GO THROUGH INORGANIC CHEMISTRY, I feel THE toughest reactions r the reactions of NaOH???????.. so I m giving its reactions hope it might be helpful to u???.. NaOH + B -------à Na3BO3 NaOH + Na2B4O7 -------à NaBO2 NaOH + B2O3 -------à NaBO2 NaOH(cold) + Cl2 -------à NaCl + NaClO NaOH(HOT) + Cl2 -------à NaCl +NaClO3 NaOH +
more ...
submitted by DON007 (1458 m) on 18 May 2007 01:14:06 IST (4 comments 200 views)
some points about groups and periods in chemistryyyyyyy...... 1)elements of second period are called bridge atoms.. 2)their properties resembles with diagonal element of third period 3)elements of third period are called typical elements 4)for iso electronic ions , size depends on nuclear charge....greater the nuclear charge , smaller is the size 5)ionization energy always has a +ive value 6)Most of E.A are +ive , however some of elements like He have -ive value of 1st I.E. 7)effective nuclear charge = Z - S...(z = nuclear charge , s = screening constant)
more ...
submitted by chimanshu_007 (11504 m) on 11 May 2007 13:54:16 IST (10 comments 222 views)
some imp. pts in "INORGANIC" fused AgCl with Na2CO3 gives Ag. an inorganic compound first melts then resolidifies to liberate a gas it will be KClO3 alkali metals are good conductors of heat and electricity due to ammoniated cations present Mg burns in N2 only to give Mg3N2 setting of cement is an exothermic process baryta is BaO and baryta water is Ba (OH)2 Ca on exposure in moist air forms a layer on the surface of .........CaCO3. Ca(OH)2 nitrolium is CaCN2 + C Mg forms an solid basic oxide at room tem
more ...
submitted by chimanshu_007 (11504 m) on 7 May 2007 16:26:31 IST (13 comments 388 views)
Alloys of magnesium Magnox (aluminium) T-Mg-Al-Zn (Bergman phase) is a complex metallic alloy Elektron Alloys of aluminium Main article: Aluminium alloys Al-Li (lithium) Duralumin (copper) Nambe (aluminium plus seven other undisclosed metals) Silumin (silicon) AA-8000: used for building wire in the U.S. per the National Electrical Code Magnalium (5% magnesium)/used in airplane bodies, ladders,etc. Aluminium also forms complex metallic alloys, like ?-Al-Mg, ?'-Al-Pd-Mn, T-Al3Mn Alloys of potassium NaK (sodium) Alloys of iron See also: Category:Ferrous alloys Steel (carbon) (category:steels) Stainl
more ...
submitted by chimanshu_007 (11504 m) on 27 Apr 2007 21:42:25 IST (1 comments 282 views)
![[Avatar]](/templates/default/images/img/no-pic.gif)
