Which symbol correctly represents an element (D) whose atoms contain 15 protons and 20 neutrons?
A. 20/15 D
B. 15/20 D
C. 35/15 D
D. 15/35 D
C?
If the 35 is a superscript and the 15 is a subscript, then C is correct.
To determine the correct symbol that represents an element with 15 protons and 20 neutrons, you need to understand how atomic symbols are written. Atomic symbols consist of a chemical symbol followed by two numbers: the atomic number (number of protons) and the mass number (number of protons and neutrons combined).
In this case, the element has 15 protons and 20 neutrons. The atomic number represents the number of protons, so 15 is the atomic number. The mass number is the sum of the protons and neutrons, so the total number of nucleons is 15 protons + 20 neutrons, which equals 35.
Therefore, the correct atomic symbol for the element (D) with 15 protons and 20 neutrons is:
C. 35/15 D
The chemical symbol "D" is followed by the mass number over the atomic number (35/15), indicating that the element has 35 nucleons in total (protons + neutrons) and 15 protons specifically.