Answer
The estimated mass of the atom is 70 amu...
Explanation
An atom has a proton mass of 35 and a neutron mass of 35 , Mass of an atom is equal to the sum of number of protons and number of neutrons .
In this case , number of protons p = 35 Number of neutron n = 35 So , the estimated mass of the atom will be :-
M 35 protons + 35 neutrons = 70 amu
hope this answer correct (^^)....
