... f0 tltrchtfcs0 tbtcf15tinsrsid15550574 tpar SSIttpnseclvl1tpnucrmtpnqctpnstart1tpnindent720tpn
hang Itpntxta .SSIttpnseclvl2tpnucltrtpnqctpnstart1tpnindent720t
pnhang Itpntxta .SSIttpnseclvl3tpndectpnqctpnstart1tpnindent720tpn
hang Itpntxta .SSIttpnseclvl4tpnlcltrtpnqctpnstart1tpnindent720t
pnhang Itpntxta SSIttpnseclvl5tpndectpnqctpnstart1tpnindent720tpnh
ang Itpntxtb SItpntxta SSIttpnseclvl6tpnlcltrtpnqctpnstart1tpnindent720tp
nhang Itpntxtb SItpntxta SSIttpnseclvl7tpnlcrmtpnqctpnstart1tpnindent720tpn
hang Itpntxtb SItpntxta SSIttpnseclvl8tpnlcltrtpnqctpnstart1tpnindent720tp
nhang Itpntxtb SItpntxta SSIttpnseclvl9tpnlcrmtpnqctpnstart1tpnindent720tpn
hang Itpntxtb SItpntxta SStpardtplain tltrparts15tqc tli0tri0tidctlpartaspalphataspnumtfaautotadjustrig
httrin0tlin0titap0 trtlchtfcs1 taf0tafs50talang1025 tltrchtfcs0 tf37tfs50tlang1033tlangfe2052tcgridtlangnp1033tlan
gfenp2052 Itrtlchtfcs1 taf0 tltrchtfcs0 tbtf0tfs42tlang1048tlangfe2052tlangnp1048tinsrsid1
5550574 Forme alotropice ale Carbonuluitpar Stpard tltrparts15tqc tli0tri0tidctlpartaspalphataspnumtfaautotadjustrig
httrin0tlin0titap0 Itrtlchtfcs1 taf0 tltrchtfcs0 tbtf0tfs42tlang1048tlangfe2052tlangnp1048tinsrsid1
5550574 - Diamantul si grafitul -tpar Stpardtplain tltrparts17tqr tli0tri0tidctlpartaspalphataspnumtfaautotadjustrig
httrin0tlin0titap0 trtlchtfcs1 tabtaf1tafs28talang1025 tltrchtfcs0 tbtf1tfs28tcf3tlang1048tlangfe2052tcgridtlangnp104
8tlangfenp2052 Itrtlchtfcs1 taf1 tltrchtfcs0 tf36tfs32tcf9tinsrsid15550574 tpar Stpardtplain tltrparts16tqj tfi720tli0tri0tidctlpartaspalphataspnumtfaautotadj
ustrighttrin0tlin0titap0 trtlchtfcs1 tabtaf1tafs28talang1025 tltrchtfcs0 tbtf1tfs28tlang1048tlangfe2052tcgridtlangnp1048tla
ngfenp2052 Itrtlchtfcs1 taf1 tltrchtfcs0 tf36tfs24tcf13tinsrsid15550574 tpar Stpard tltrparts16tqj tfi720tli0tri0tidctlpartaspalphataspnumtfaautotadj
ustrighttrin0tlin0titap0 Itrtlchtfcs1 taf1 tltrchtfcs0 tf0tfs24tinsrsid15550574 Alotropia este proprietatea unor elemente chimice de a se prezenta in una sau mai multe forme cristaline sau moleculare. Ea este determinata de formarea unor molecule cu numar diferit de atomi si modificatii cristaline diferite. Formele alotropice difera prin proprietatile fizice si chimice.tpar tpar Carbonul este un nemetal, situat in grupa a IVSItrtlchtfcs1 taf1 tltrchtfcs0 tf0tfs24tsupertinsrsid15550574 aSItrtlchtfcs1 taf1 tltrchtfcs0 tf0tfs24tinsrsid15550574 . Se noteaza prescurtat C si se gaseste in doua stari alotropice diamant si grafit.tpar tpar In cristalul de diamant format din atomi de carbon, atomii din retea se unesc prin legaturi covalente. Fiecare atom de carbon pune in comun cei 4 electroni de valenta cu alti 4 atomi vecini.tpar tpar In cristalul de carbon, atomii de retea formeaza tot legaturi covalente, dar fiecare atom de carbon pune in comun 3 electroni cu alti 3 atomi vecini.tpar tpar Covalenta reprezinta numarul de electroni unui atom pusi in comun cu electronii altui atom. Legaturile covalente sunt orientate in spatiu, sunt rigide si mai puternice decat legaturile ionice. tpar tpar In grafit se gaseste un tip special de retea atomica numita retea statificata, care este o retea atomica hexagonala formata din plane paralele de atomi de carbon.tpar tpar Diamantul are o retea cubica, iar cristalele de grafit sunt alcatuite din straturi paralele de hexagoane de atomi de carbon, care formeaza o retea stratificata atomica. Atomi de carbon dintr-un plan ocupa colturile unor hexagoane regulate.tpar Stpard tltrparts16tqj tli0tri0tidctlpartaspalphataspnumtfaautotadjustrig
httrin0tlin0titap0 Itrtlchtfcs1 taf1 tltrchtfcs0 tf0tfs24tinsrsid15550574 tpar Stpard tltrparts16tqj tli0tri0tidctlpartaspalphataspnumtfaautotadjustrig
httrin0tlin0titap0 Itrtlchtfcs1 taf1 tltrchtfcs0 tf0tfs24tinsrsid15550574 ttab Proprietatiile fizice ale diamantului cat si ale grafitului sunt determinate de structura lor. Astfel, atat diamantul cat si grafitul sunt substante in stare ... Download