Francium was discovered by Marguerite Perey in 1939 when she was researching the radioactive decay of actinium-227. The discovery took place at the Curie Institute in Paris. The element takes its name from the country of its discovery â France.
Worldâs Biggest Dog, Worldâs Heaviest Dog. Hercules: The Worldâs Biggest Dog Ever According to Guinness World Records. Hercules was recently awarded the honorable distinction of Worlds Biggest Dog by Guinness World Records. Hercules is an English Mastiff and whas a 38 inch neck and weighs 282 pounds.
This breed comes in several colors including black, blue, mahogany and tawny. (Photo: Stanimir G.Stoev/Shutterstock) Mastiff breeds are certainly among the largest dogs in terms of sheer mass. The Neapolitan mastiff originated in southern Italy. Used as a guard dog, the average male mastiff stands between 26-31 inches tall and weighs a hefty 130-155 pounds.