Which of the following is a reasonable ground-state electron configuration? 1s21p62d2 1s22s42p6 1s22s22p5 1s22s22d6

Answer is: 1s22s22p5.

1) Electron configuration 1s²1p⁶2d², this is not reasonable because 1p and 2d oritals do not exist.

2) Electron configuration 1s²2s⁴2p⁶, this is not reasonable because s orbitals only contain 2 electrons.

3) Electron configuration 1s²2s²2p⁵ is of an element fluorine. Fluorine (F) has atomic number 9, which means it has 9 protons and 9 electrons.

4) Electron configuration 1s²2s²2d⁶, this is not reasonable because 2d orbitals do not exist.

mechanics (greek   is that area of science concerned with the behaviour of physical bodies when subjected to forces or displacements, and the subsequent effects of the bodies on their environment. the scientific discipline has its origins in ancient greece with the writings of aristotle and archimedes[1][2][3] (see history of classical mechanics and timeline of classical mechanics). during the early modern period, scientists such as galileo, kepler, and newton laid the foundation for what is now known as classical mechanics. it is a branch of classical physics that deals with particles that are either at rest or are moving with velocities significantly less than the speed of light. it can also be defined as a branch of science which deals with the motion of and forces on objects. the field is yet less widely understood in terms of quantum theory.

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