This compound is named potassium chloride. Example 5: Write the name of the following formula: Na2S. First symbol is Na, so the first part of the name is sodium. (Note the presence of the subscript does not play a role in this name.) Second element is sulfur (from the symbol S), so the name is sulf + ide = sulfide. This compound is named sodium sulfide.
The viviparous sharks who carry the eggs until the pups are born, have different gestation periods. The dogfish shark is known to keep their eggs for 18 to 24 months. The bull shark gestation is about one year. The hammerhead shark gestation period is from 7 to 12 months. Other species that are ovoviviparous carry the eggs until the pups born alive and fully developed. They also have long gestation periods. The tiger shark gestation is about 14 to 16 months.
Female killer whales reach sexual maturity when they grow to about 15-18 feet (4.6 m-5.4 m) long, depending on geographic region. The gestation period for killer whales varies from 15-18 months. Birth may take place in any month--there is no distinct calving season. Calves are nursed for at least 1 year, and may be weaned between 1-2 years old. The birth rate for killer whales is not well understood, but, in some populations, is estimated as every 5 years for an average period of 25 years. Killer whales are highly social animals that occur primarily in relatively stable social groups that often range in size from 2 to 15 animals.