To determine the complete symbol of the atom, we need to identify its mass number and atomic number. The atomic number is equal to the number of protons, which in a neutral atom is also the number of electrons. In this case, the atom has 15 electrons, so it has an atomic number of 15.
Next, we calculate the mass number, which is the sum of protons and neutrons. Since the atomic number is 15, the atom has 15 protons. It also contains 19 neutrons. Therefore, the mass number can be calculated as follows:
Mass Number = Protons + Neutrons = 15 + 19 = 34
Now that we have both the atomic number and the mass number, we can write the complete symbol for the atom. The element with atomic number 15 is phosphorus (P). The complete symbol is written in the format of:
⁴⁴P or P-34
Thus, the complete symbol, including the mass number and atomic number, is 1534P.