Explain what happens when an element undergoes radioactive decay ?

When an element goes under radioactive decay the element spontaneously emits radiation or radioactive particles such as alpha, beta and gamma particles.  When this happens, the element usually transform into another atom by changes in the number of protons except in the cause of gamma particles which energy is released from the atom. 

(4) HBr and H2SO4 is the correct answer.
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