Final answer:
The chemical elements with atomic numbers greater than 55 and atomic masses less than 141.0 u are Barium (Ba), Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Promethium (Pm), Samarium (Sm), Europium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (H-o), Erbium (Er), Thulium (Tm), Ytterbium (Yb), and Lutetium (Lu).
Step-by-step explanation:
To write the symbols for chemical elements, we need to identify the elements that have an atomic number greater than 55 and an atomic mass less than 141.0 u. Let's refer to the periodic table for this information:
The elements that meet the criteria are: Barium (Ba), Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Promethium (Pm), Samarium (Sm), Europium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (H-o), Erbium (Er), Thulium (Tm), Ytterbium (Yb), and Lutetium (Lu).
These are the chemical elements with atomic numbers greater than 55 and atomic masses less than 141.0 u.