What does it mean when atoms are sticking to each other ?
Benzene presents a special problem in that , to account for all the bonds , there must be alternating double carbon bonds:In 1865 , German chemist August Wilhelm von Hofmann was the first to make stick - and - ball molecular models , which he used in lecture at the Royal Institution of Great Britain , such as methane shown below:The basis of this model followed the earlier 1855 suggestion by his colleague William Odling that carbon is tetravalent .