The alkaline earth metals are six chemical elements in column (group) 2 of the Periodic table.They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).They have very similar properties: they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure.hey are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). They have very similar properties: they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure.
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.
Whales typically give birth to one calf at a time, although twin fetuses can occur on rare occasions. Mature females of most species, including humpback, beluga and blue whales, usually reproduce every two to three years.The average time between gestation periods for sperm whales is three to four years.ewborn beluga whale calves typically weigh about 175 lbs. A right whale calf's birthweight generally is about 500 lbs. Gray whales weigh 1,100 to 1,500 lbs. at birth.