Question

why might a source have a longer half-life nuclei

Answer 1

Answer:

Half-life, in radioactivity, the interval of time required for one-half of the atomic nuclei of a radioactive sample to decay (change spontaneously into other nuclear species by emitting particles and energy), or, equivalently, the time interval required for the number of disintegrations per second of a radioactive ...

Answer 2

Answer:

The 'half-life' of a radioactive nucleus is one of its main features with the nature of radiations it emits. It determines how quickly it will decay and for how long we need to worry about its radiations. Half-lives can range from a fraction of a second to billions of years.