Simplify the following text for a Grade 9 native English-speaking person.
Original: Tantalum ( ; from Greek mythology : Tantalus , a son of Zeus and the father of Pelops , Niobe and Broteas ) is a chemical element previously known as tantalium with the symbol Ta and atomic number 73 .
Simplified: Tantalum was named tantalium . It has the chemical symbol Ta .