What do u mean by electronic configuration? What are basic requirements while writing electronic configuration of an element (atom) ?

Electronic configuration, also called electronic structure, the arrangement of electrons in energy levels around an atomic nucleus. In terms of a more refined, quantum-mechanical model, the K–Q shells are subdivided into a set of orbitals (see orbital), each of which can be occupied by no more than a pair of electrons. Electron configurations are written so as to clearly display the number of electrons in the atom as well as the number of electrons in each orbital. Each orbital is written in sequence, with the number of electrons in each orbital written in superscript to the right of the orbital name.

Yes that is right I look it up thanks for the points

There is no reason to think the results are biased or not conducted properly but you should not assume the results are correct just because they were done in a laboratory so the answer would be c. it is likely to be reliable because the results support the conclusion presented.

Answer///an early form of the atomic theory; dalton atomic theory;