A 2s orbital contains electron density near the nucleus due to its spherical shape and the presence of a radial node. This node creates a region where the probability of finding an electron is zero, but the wave function still allows for electron density in the inner regions. The electron density distribution reflects the balance between attractive forces from the nucleus and the repulsive forces from other electrons. The presence of this density near the nucleus is a fundamental characteristic of atomic orbitals. Understanding this concept is crucial for grasping the behavior of electrons in atoms.