A simple cation (obtained from a single atom) takes its name from the name of the element. 3. A simple anion (obtained from a single atom) is named by taking the first part of the element name (the root) and adding the letters IDE. 4. Write the name for the compound by combining the names of the ions.
1 Blue whales give birth after 11 â 12 months of pregnancy and it is estimated that female whales give birth every 2 â 3 years.  killer whale have a pregnancy period of 15 â 18 months, however it is believed that the average pregnancy period is about 17 months. (Females killer whales give birth every 3 â 5 years).
Other animals that have gestation periods closest to that of humans are: dolphins - 276 days, chimpanzee - 237 days and cattle - 280 days. 494. About the Author. The shortest gestation period known in mammals is approximately 12 days. It is shared by the American or Virginian opossum (Didelphis marsupialis); the rare water opossum, or yapok (Chironectes minimus) of northern South America and the eastern native cat (Dasyurus viverrinus) of Australia.