What is one Becquerel (Bq) equivalent to?

One Becquerel (Bq) is defined as one disintegration or decay of a radioactive substance per second. This unit measures the activity of a radioactive material, providing a standard for quantifying how frequently nuclear decay events occur. When a sample is said to have a radioactivity level of one Bq, it indicates that there is one decay event happening every second, highlighting the dynamic nature of radioactive decay.

In contrast, the other options refer to different time intervals for decay events, which do not align with the definition of a Becquerel. Specifically, one decay per minute or one decay per hour reflects a much lower rate of decay than one per second, and one decay per day is an even less frequent occurrence. These measurements correspond to different units of activity, such as decays per minute, hour, or day, rather than the standard unit of activity that the Becquerel represents.