These elements, especially carbon and silicon, have a strong propensity for covalent bonding, which usually brings the outer shell to eight electrons.

Bonds in these elements often lead to hybridisation where distinct s and p characters of the orbitals are erased.

Among main group (groups 1, 2, 13–17) alkyl derivatives QRn, where n is the standard bonding number for Q (see lambda convention), the group 14 derivatives QR4 are notable in being electron-precise: they are neither electron-deficient (having fewer electrons than an octet and tending to be Lewis acidic at Q and usually existing as oligomeric clusters or adducts with Lewis bases) nor electron-excessive (having lone pair(s) at Q and tending to be Lewis basic at Q).

In the case of carbon, the high bond dissociation energy of the C–C bond and lack of electronegativity difference between the central atom and the alkyl ligands render the saturated alkyl derivatives, the alkanes, particularly inert.

Germanium bonds to all natural single chalcogens except polonium, and forms dioxides, disulfides, and diselenides.

[10] The boiling points of the carbon group tend to get lower with the heavier elements.

[13] Carbon's crystal structure is hexagonal; at high pressures and temperatures it forms diamond (see below).

Silicon and germanium have diamond cubic crystal structures, as does tin at low temperatures (below 13.2 °C).

[18] Silicon is present in the Earth's crust at concentrations of 28%, making it the second most abundant element there.

[18] Flerovium doesn't occur in nature at all, so it only exists in particle accelerators with a few atoms at a time.

[18] Carbon, tin, and lead are a few of the elements well known in the ancient world, together with sulfur, iron, copper, mercury, silver, and gold.

[20] Silicon as silica in the form of rock crystal was familiar to the predynastic Egyptians, who used it for beads and small vases; to the early Chinese; and probably to many others of the ancients.

Many of the naturally occurring compounds or silicate minerals were used in various kinds of mortar for construction of dwellings by the earliest people.

It appears that bronzes, which are alloys of copper and tin, were used by prehistoric man some time before the pure metal was isolated.

Bronzes were common in early Mesopotamia, the Indus Valley, Egypt, Crete, Israel, and Peru.

Tin mines were operating in both the Inca and Aztec areas of South and Central America before the Spanish conquest.

The Romans used it for tablets, water pipes, coins, and even cooking utensils; indeed, as a result of the last use, lead poisoning was recognized in the time of Augustus Caesar.

The compound known as white lead was apparently prepared as a decorative pigment at least as early as 200 BCE.

Germanium is one of three elements the existence of which was predicted in 1869 by the Russian chemist Dmitri Mendeleev when he first devised his periodic table.

[18] The first attempt to discover flerovium (then referred to as "element 114") was in 1969, at the Joint Institute for Nuclear Research, but it was unsuccessful.

[22] Silicon dioxide has a wide variety of applications, including toothpaste, construction fillers, and silica is a major component of glass.

Lead was historically used in gasoline in the form of tetraethyllead, but this application has been discontinued due to concerns of toxicity.

[23] Carbon's allotrope diamond is produced mostly by Russia, Botswana, Congo, Canada, South Africa, and India.

Germanium-containing ores are first treated with chlorine to form germanium tetrachloride, which is mixed with hydrogen gas.

4 million metric tons of lead are newly mined each year, mostly in China, Australia, the United States, and Peru.

[6] Carbon's importance to life is primarily due to its ability to form numerous bonds with other elements.

[clarification needed] These plants, which include grains and vegetables contain roughly 0.05 parts per million of germanium.

[18] Lead has no known biological role, and is in fact highly toxic, but some microbes are able to survive in lead-contaminated environments.

However, silicon dioxide dust, such as that emitted by volcanoes can cause adverse health effects if it enters the lungs.

Organic tin compounds, such as trimethyltin and triethyltin are highly toxic, and can disrupt metabolic processes inside cells.