If the nuclear model of the atom shell, when determining the charge of the nucleus was considered one proton shielding others. In charge of the nucleus of copper Chadwick received equal 29,3- protons still not much more protons in silver, and the measured charge is 46.3 which is less than 47, and for platinum experiment gave a result of 77.4 or less than 78.

    In platinum in the nucleus of many protons there is more screening and in my charge in 82 points more untrue. See the table below.