Two wires a and b of the same material, having radii in the ratio 1 : 2 and carry currents in the ratio 4 : 1. the ratio of drift speeds of electrons in a and b is

Daughter element the new element produced along with a decay particle in a nuclear transmutation 2. half-life the substance that decays in a nuclear transmutation 3. parent element the change of one chemical element into another by nuclear decay or radioactive bombardment 4. transmutation the time required for the decay of one-half of the atoms in a sample of radioactive material