If what you mean is,is an atomic bomb stronger or weaker then a regular bomb then it's the atomic bomb,a regular bomb would have only damaged Hiroshima not completely killed it( the U.S also bomb Nagasaki)
The "Hydrogen" bomb refers to the "Fusion" of a Hydrogen Isotope on an Atomic scale by way of steps of mutiple reactions thus yielding a much more powerful explosion upwards of 500 Million Tons of...