The nitrogen cycle is the process by which nitrogen is converted between its various chemical forms. This transformation can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification. The majority of Earth's atmosphere (78%) is nitrogen, making it the largest pool of nitrogen.
Topher Grace. Christopher John Topher Grace (/ËtoÊfÉr/; born July 12, 1978) is an American actor. He is known for his portrayal of Eric Forman on the Fox sitcom That '70s Show, Eddie Brock/Venom in the Sam Raimi film Spider-Man 3, Carter Duryea in the film In Good Company and Edwin in the 2010 film Predators. 1 Early life.
Topher Grace's Relationships. 1  Ashley Hinshaw. Actress. 2  Camilla Belle. Actress. 3  Katie Cassidy. Actress.  Teresa Palmer. 1  Actress. Ivanka Trump. Model.  Emmy Rossum. 1  Actress. Ginnifer Goodwin. Actress.  Anne Hathaway. Actress.