Answer: 97
Explanation:
The element Ru is <u>Ruthenium</u> which has <u>44 protons</u>.
In this case, our atom is an isotope with <u>53 neutrons</u>.
With this information, we can use the mass number formula to find this atom's mass number.
mass number = protons + neutrons
mass number = <u>44 protons</u> + <u>53 neutrons</u>
mass number = <u>97</u>
