Five chemistry inventions that enabled the modern world

What do pencillin, polythene and Mexican yam have in common?

This article was first published on The Conversation.

Did you know that the discovery of a way to make ammonia was the single most important reason for the world's population explosion from 1.6 billion in 1900 to 7 billion today? Or that polythene, the world's most common plastic, was accidentally invented twice?