Dictionary of Chemistry [6th Ed.]

silicon 482

s

silicides are structurally similar to

the interstitial carbides but the range

encountered is more diverse. They

react with mineral acids to form a

range of *silanes.

siliconSymbol Si. A metalloid el-

ement belonging to *group 14 (for-

merly IVB) of the periodic table; a.n.

14; r.a.m. 28.086; r.d. 2.33; m.p.

1410 °C; b.p. 2355°C. Silicon is the

second most abundant element in

the earth’s crust (25.7% by weight) oc-

Si

O

O

O O

=

SiO4–as in Be 2 SiO 4 (phenacite)

Si 2 O2– as in Sc 2 Si 2 O 7 (thortveitite)

Si 3 O6– 9 as in BaTiSi 3 O 9 (bentonite) Si 6 O12– 18 as in Be 3 Al 2 Si 6 O 18 (beryl)

5

4

single chain : pyroxenes

double chain : amphiboles sheet : micas

Structure of some discrete silicate ions

Structure of some polymeric silicate ions

Silicate minerals

Structure of some polymeric silicate ions

Structure of some discrete silicate ions