The number 4 in the 4/2He indicates the atomic mass number of helium.
Answer: Option 3
Explanation:
The elements present in periodic table generally represented as [tex]X_{Z}^{A}[/tex]. Here X will be the element in the periodic table, A is the atomic mass number of the element X and Z is the atomic number of the element X.
So, the number 4 is the atomic mass number of He and He-4 is the stable isotope of helium which can also be termed as alpha particle.
Mass number = number of protons + neutrons count.
Thus the number 4 denotes the Helium's atomic mass number.
