Question

Why is silicon not suitable for making covalent bonds stable and strong enough to form the basis of

living organisms, even though it is just below carbon on the periodic table?
a) Silicon is too large for its nucleus to attract the valence electrons of neighboring atoms enough to hold
molecules together sufficiently.
b) Silicon is too small for its nucleus to attract the valence electrons of neighboring atoms enough to hold
molecules together sufficiently.
c) Silicon is too large for its nucleus to attract the protons of neighboring atoms enough to hold molecules
together.
d) Silicon is too small for its nucleus to attract the protons of neighboring atoms enough to hold
molecules together.

Answer 1

Silicon cannot form strong, stable covalent bonds like carbon does, particularly because it doesn't form strong double bonds. Consequently, silicon-based compounds, such as silicon dioxide, form solid networks rather than gaseous byproducts, making them less suitable for forming biological molecules.

Step-by-step explanation:

Silicon is not suitable for forming the basis of biological molecules primarily because of its inability to form strong, stable covalent è bonds as carbon does. The strength of a covalent bond, such as the carbon-carbon bond in organic compounds, is indicated by the amount of energy needed to break it. While silicon can form single bonds with oxygen in silicon dioxide to create a vast three-dimensional network, these bonds are not as robust as the è bonds seen in carbon compounds.

Additionally, the physical and chemical properties of silicon-based compounds are quite different from those of carbon. For example, silicon dioxide forms a solid network which is insoluble in water, making it hard to excrete from biological systems, unlike the gaseous CO2 produced from carbon-based compounds.

Finally, although elements like silicon can form multiple bonds, they are not as strong or as common as those in carbon compounds. Multiple bonds involving silicon are also presumed to be significantly weaker than similar bonds between lighter atoms such as carbon.