Identify the correct statements from the following: A. Heisenberg...

Statement A is correct. Heisenberg's uncertainty principle is applicable to microscopic particles such as electrons.

Statement B is correct. The size of an orbital increases with an increase in the principal quantum number $n$. Thus, the size of the $3p_x$ orbital is greater than that of the $2p_x$ orbital.

Statement C is incorrect. The energy of an orbital depends on the effective nuclear charge. Since the nuclear charge of Li ($Z=3$) is greater than that of H ($Z=1$), the energy of the $2s$ orbital of Li is lower than that of the $2s$ orbital of H.

Statement D is correct. Chromium ($Z=24$) has an anomalous electronic configuration of $[\text{Ar}] 3d^5 4s^1$ due to the extra stability of the half-filled $d$-subshell.

Therefore, statements A, B, and D are correct.

Answer: A, B and D Only