Why carbon atom can bind rangkap1, 2,3 whereas a class can not be atomic (Si, Ge, Pb) ?

 because the C atom has the electron configuration of 2.4. fourth atomic valence electrons distributed symmetrically on the 4th position, and the ability to bind to the C atom different from another atom.
while the Si atom has a configuration elaktron 2.8,4. has the same valence elaktron atom C however, elaktron lies in the valence shell of silicon atoms C in the third while the second skin, so the atomic radius of Si atoms is greater than C. So Si-H bond in SiH4 bond is weaker than the CH bond in CH4 bond.
C atom has a valence electron atomic radius of the smallest among the atoms of other elements is easier digolongan IVA.Hal C atoms to form covalent bonds with other atoms, especially with H, O, N, and halogen atoms (F, Cl Br, I) formed covalent bonds meet the rules oktet.Atom C can form up to 4 bonds kovalenyang bonds stronger than covalent bonds lainsehingga carbon compounds are stable.