The type of radioactive decay in which the mass number and atomic number remain unchanged is (2 points) Select one: a. beta radiation. b. alpha radiation. c. positron radiation. d. gamma radiation.

d.

Explanation:

a. beta radiation - electrons that have negative charge, and when they leave a nucleus , the charge or atomic number of the nucleus will change.

b. Alpha radiation - nuclei of He, atomic number and mass number will be changed.

c. positron radiation - positrons are similar to electrons but have positive charge, so , the charge or atomic number of the nucleus will change.

d. gamma radiation is electromagnetic waves, does not have charge and mass.

im pretty sure its b