While a certain isotope decays, it emits photons. what kind of decay is happening a) alpha decay b) beta decay c) gamma decay d) positron decay

Gamma decay.

Explanation:

Gamma decay is generally observed after some alpha or beta decay from a radioactive element. The daughter nucleus obtained after the two decay may emit gamma rays. These gamma rays are considered to be energy particles or photons. These are the most energetic electromagnetic waves with lowest wavelength.

c- cold periods in earth's history during which glaciers covered much of the surface.

explanation: