strength vs young's modulus
Actually, little of the materials’ strength is explained by atomic structure: rather it is the micro- and meso- structure that is more important. Remember, yield and tensile strength are best thought of in terms of resistance to dislocation movement. That’s why quench-and-temper hardening, or precipitation hardening, or solid solution strengthening work: because they make it more difficult for dislocations to move through the material.
Yet elastic modulus is entirely stretching under a load that comes back, so it is due to the bonds between atoms stretching. Certainly there will be more stretching across grain boundaries where the bonding is weaker, but it’s always going to be atom-to-atom stretching that gives you elastic deformation.