Egyptians would revolutionize the literary world by producing a smooth, flexible writing material that could accept and retain ink without a blur or smudge. This material, papyrus, would remain in use for longer than any other material in the history of written documents.By the 11th century, papermaking was brought to Europe.
European improvements to the papermaking process came in the 19th century with the invention of wood-based papers.Before the invention and current widespread adoption of automated machinery, all paper was made by hand.Paper made from other fibers, cotton being the most common, tends to be valued higher than wood-based paper.
Tetravalent
We have already seen an example of how a covalent bond can form between two hydrogen atoms producing molecular (H2) as opposed to the atomic form of hydrogen. ... As in all its compounds and its elemental forms, carbon is tetravalent, which means that it always forms four bonds.
