Why carbon has a double bond of 1, 2, and 3? Why is that?In the carbon atoms are bonded neighbor three kemukinan, first forming a single bond, double bond and a triple bond. For simplicity we can be compared to a single bond occurs from s and is called the bonding orbital (σ) sigma sp3 hybrid orbitals and molecular forms an angle of 109.5 o tetrahedron. Compounds with a single bond called saturated hydrocarbons.Hydrocarbons with double bonds occur in p orbitals, and the bond is known as π bond, the double bond angle changes due to two parallel p orbitals positioned so as to form sp2 orbital (flat triangle) and the angle formed is 120o. Similarly, a triple bond, there are two parallel p orbitals in a position that alter sp orbitals form a (planar form) with an angle of 180 °. Molecular forms of saturated hydrocarbons and unsaturated shown in Figure 12.3. For the hydrocarbons that have double bonds called unsaturated hydrocarbons.
 Figure 12.3. Σ bond, π, the saturated hydrocarbons and unsaturatedThe carbon atoms in the hydrocarbon compounds having different positions. Let us consider the following formula woke in Figure 12.4.
 Figure 12.4. The position of carbon atoms in the hydrocarbonAll carbon atoms (red) which can bind three hydrogen atoms and plays on the edge, called the primary carbon atom. Carbon atom number 3 (green) that bind two atoms of hydrogen called a secondary carbon atom. Similarly, the carbon atom with only one hydrogen atom (gray) has a position as a tertiary carbon atom.Each carbon atom in terms of hydrocarbon compounds can bind to other atoms such as hydrogen, oxygen, nitrogen, sulfur, chlorine and others. Differences atom bound to cause changes in particular polarity, causing differences in the chemical properties of the molecule is formed. It can be observed in Figure 12.5.
 Figure 12.5. Polarization of hydrocarbons due to polar groupsIn general, hydrocarbons have such characteristics, built by the framework carbon atoms, a bond is a covalent bond forming compounds. This compound is a low boiling point corresponding to the reduced number of constituent carbon atoms, flammable. For hydrocarbon compounds that bind to the H atom is polar, and if it binds other atoms such as oxygen, nitrogen, sulfur, chloride causes more polar molecules.