Answer:
z+4
Explanation:
An isotope of an element, atomic number Z, has a mass number 2z+4. How many neutrons are there in the nucleus of the element?o
protons + neutrons =mass number
so
z +neutrons = 2z+4
neutrons = 2z+4 - z=z+4 which is the # of neutrons in the nucle
us
