Answer:
the mass is 7
Step-by-step explanation:
The atomic mass equation for an atom is Protons + neutrons = atomic mass. The reason the electrons aren't included here is because their masses are EXTREMELY SMALL, to the point where there wouldn't be any point including them- it wouldnt really change your answer
Since there are 3 protons and 4 neutrons, we plug them in to the equation
3+4 = atomic mass
7 = atomic mass
so your atomic mass is 7
Hope this helps :)