Answer: multiple apply them together then divide them
Explanation:
Adding or removing neutrons from the nucleus are how isotopes are created. Protons carry a positive electrical charge and they alone determine the charge of the nucleus. Adding or removing protons from the nucleus changes the charge of the nucleus and changes that atom's atomic number.
The number of neutrons is variable, resulting in isotopes, which are different forms of the same atom that vary only in the number of neutrons they possess. Together, the number of protons and the number of neutrons determine an element's mass number.
tbh google
hope it helps
It would be 187 75 Re since 76 - 1 is 75 and number 2 would be beta particle and a positron.
