Chemical reactions are the backbone of modern society: the energy we use, the medicines we take, our housing materials, even the foods we eat, are created by reacting different substances together. If we zoom in, it’s the atoms within these substances that rearrange themselves to give rise to new substances with the properties we need.

However, chemical reactions are far from perfect. They're often inefficient and their waste products can be harmful to the environment. Getting to grips with what goes on at the scale of individual atoms has long been a sticking point.

Dame Pratibha Gai has spent much of her career pioneering novel microscopes to bring this seemingly inaccessible atomic world into sharp focus. Now Emeritus Professor of Chemistry at York University, her microscope, known as the environmental transmission electron microscope, is housed in labs around the world. It allows scientists, like herself, to observe chemical reactions in real-time, in exquisite atomic detail, and tinker with them to create products that are not only better for all of us, but also the environment.

Presented by Jim Al-Khalili