You're always going to have at least n + 1 chrome.exe processes, where n is the number of unique domains you have open across all visible tabs. The +1 is for the "Browser" process coordinating everything else. (e.g. I have 5 tabs open, 4 for SuperUser, 1 for another site. I have 2 Tab processes open)
You'll also have processes for any extensions that might have a background window open. (e.g. Adblock Plus, Ghostery, Stylish, NinjaKit all require an extra process)
Pressione Shift + Esc ou vá para o Gerenciador de tarefas do Chrome (no submenu Ferramentas do menu / dependendo da versão do Google Chrome em execução) para ver uma lista de todos os processos e para os quais eles estão sendo usados.