# The electron density between 1s and 2s orbital is (A) High (B) Low (C) Zero (D) Abnormal

Zero

We know the region between 1s and 2s orbital is a nodal plane. Nodal plane is the region in which the probability of finding an electron is zero. Thus the electron density is zero since the region between 1s and 2s orbital is a nodal plane.

Hence, the correct option is (C)