The neutral atom with an atomic number of 19 and a mass number of 39. element name: atomic symbol: ??

Step 1 ：The neutral atom with an atomic number of 19 and a mass number of 39 is asked for its element name and atomic symbol.

Step 2 ：The atomic number of an element corresponds to the number of protons in its nucleus, and it is unique for each element. Therefore, the atomic number can be used to identify an element.

Step 3 ：The element with an atomic number of 19 is Potassium.

Step 4 ：The atomic symbol for Potassium is K.

Step 5 ：Final Answer: The element with an atomic number of 19 is Potassium, with the atomic symbol \(\boxed{K}\).