Question

Which of the following cannot be emitted by radioactive substances during their decay?

• A. Protons
• B. Neutrons
• C. Helium nuclei
• D. Electrons

Answer 1

Answer: (A)

The nuclei of the radioactive substances

emit various particles as shown

below.

Alpha decay ${}_z^{A}X{\to }_{z-2}^{A-4}Y{+}_2^{4}He$

Beta decay $(B^{-}{)}_z^{A}X{\to }_{z+1}^{A}Y+e^{e-}+\overline{v}$

Beta decay $(B^{+}{)}_A^{z}X{\to }_{z-1}^{A}Y+e^{+}+v$

Electron capture ${}_z^{A}X+e^{-}{\to }_{z-1}^{A}Y+v$

Gamma decay ${}_z^{A}X{\to }_z^A+v$

As we see above in radioactive

decay protons & neutrons are not

emitted.

Hence option (A) ie proton is

the answer.