Pure forms of carbon. Carbon is everywhere: it forms rocks, plants, animals (proteins, DNA, etc), plastics, etc. Those usually contain carbon as well as other atoms, like nitrogen, oxygen and hydrogen among others. There are some materials, however, that contain only carbon.
The Healthy Pregnancy Book: Month by Month, Everything You Need to Know from America's Baby Experts (Sears Parenting Library) Paperback â September 24, 2013. Find all the books, read about the author, and more.
Public Health Agency: 'The Pregnancy Book', published 2014. Nemours Foundation: 'Pregnancy calendar â A week-by-week guide', accessed online January 2015. NHS Choices: 'Planning your pregnancy', 'From conception to birth', accessed online January 2015.