Nuclei of u-238 atoms are(1) stable and spontaneously absorb alpha particles(2) stable and spontaneously emit alpha particles(3) unstable and spontaneously absorb alpha particles
(4) unstable and spontaneously emit alpha particles

The answer is 4. Unstable nuclei divided up in a procedure called radioactive decay and produce radioactive radiation. Radioactive atoms for instance Uranium are extremely unbalanced because of weighty nucleus and therefore they produce their masses in procedure of radiations to develop stabilized.

I’m guessing you’re more alert to yourself or your surroundings if you’re more concentrated