Okay kiddo, so Benjamin Elazari Volcani was a scientist who studied tiny living things called bacteria. He wanted to know how they grow and survive in different environments. He discovered that some bacteria can live in really hot places like volcanoes and some can even survive without oxygen!
He also studied something called a "biosphere" which is like a mini-ecosystem that can support life. He found that different bacteria and other tiny creatures can live together in a biosphere and help each other survive.
In short, Benjamin Elazari Volcani was a scientist who studied bacteria and how they survive in different environments, and he also studied how tiny creatures can work together to survive in a mini-ecosystem called a biosphere.