Statement 1: The combining atomic orbitals must have the same or nearly the same energy.Statement 2: 1s orbital can combine with another 1s orbital but not with 2 s orbital because the energy of 2s orbital is appreciably higher than that of 1s orbital. This is not true if the atoms are very different.

The linear combination of atomic orbitals to form molecular orbitals takes place ifThe combining atomic orbitals must. have the same or nearly the same energyThis means that 1s orbital can combine with another 1s orbital but not with 2s-orbitals because the energy of 2s orbitals is appreciably higher than that of 1s orbital. This is not true if the atoms are very different.