Technetium ground state electronic configuration

The atom whose ground-state electron configuration is depicted is in the fifth row because it follows krypton. It has the configuration 5s2 4cr, which identifies it as technetium. Alternatively, it has 36 + 7 = 43 electrons and is the element with Z = 43. 

Use the Aufbau principle to obtain the ground-state electron configuration of technetium. 

As expected there is a close resemblance in the chemical behaviour of technetium and rhenium whereas the properties of both elements differ considerably from those of manganese. The electronic configuration of technetium in the ground state is 4d 5s. Technetium is a silver-grey metal which tarnishes slowly in moist air. 

According to the building-up principle, what is the electron configuration of the ground state of the technetium atom (atomic number 43) ... 

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