The carbon atom rings of cycloalkanes are usually shown as planar, although only the carbon ring in cyclopropane is planar. Bond angles are often distorted in cycloalkanes leading to ring strain . The greater the deviation from the terahedral angle of 109.5 degrees, the greater is the ring strain and the less stable is the cycloalkane. Cyclohexane avoids this by puckering to form the boat or the chair conformation. Physical Properties of Alkanes.
Alkanes are relatively unreactive and remain unchanged by most reagents.
The reaction that is most significant is combustion.