Chemical engineers study and develop chemically-based industrial processes by understanding how and why the elements interact. They might apply this knowledge to figuring out how to remove pollution from a river or mine, how to get plastic wrap from petrochemical products or how to burn coal more cleanly and efficiently. What chemical engineers do with chemistry very complex, but it all begins with a basic understanding of some Atoms The smallest unit of each element is the atom. Atoms are made up of three different types of particles - protons, electrons, and neutrons. Neutrons have no charge, and therefore are not attractive.
All atoms have the same number of protons and electrons, and are neutrally charged.
Protons and neutrons are the only parts of the atom which have any mass. The whole number is the element's atomic number and is equal to the number of protons it has. The other number is the element's atomic mass. Neutrons and protons have almost exactly the same mass, so you can figure out the number of neutrons in an element by subtracting the atomic number from the atomic mass.