What is the isotopic symbol for an element with 47 protons and 68 neutrons?
Answer:
\({ }_{47}^{115} \mathrm{Ag}\)
Explanation:
A neutral atom will have the same number of protons as electrons. So if the the atom has 47 electrons it will have 47 protons.
The element with 47 protons is silver Ag. Silver typically has a mass of 107.9. Which means the most common isotope of silver has 61 neutrons. An isotope with a mass of 115 \((47+68)\) would be very unstable and most likely radioactive.
47 electrons = 47 protons
The mass number equals protons + neutrons.
47+68=115
The isotope is silver 115.
\({ }_{47}^{115} \mathrm{Ag}\)