[DannyTN]

Beat me to it!

A Cobalt bomb would kill every living thing on earth.
This sounds like it would cause a lot more harm than an ordinary bomb but not completely lethal.

The half life of radioactive cobalt is 5.4 years. The half life of Tantalum varies on the isotope but looks like it is 50 to 115 days. I couldn’t find a half life on tantalum 181.

[Rurudyne]

Which brings up an interesting point: with such a short half life such weapons cannot be stored. The program to enrich the salting agent to a useful point has to be active not long before the weapons are used.

Or so it would seem to me.

[HangnJudge]

https://en.m.wikipedia.org/wiki/Tantalum

Tantalum 181 + n - Tantalum 182 T1/2=114days

[Ciaphas Cain]

We’re safe for now, at least until those damn dirty apes raid the temple a few thousand years ahead of us...

[RAWGUY]

“I couldn’t find a half life on tantalum 181.”

There is no half life for Tantalum 181, it is a stable isotope:

Isotope Half Life
Ta-179 1.8 years
Ta-180 1.2E15 years
Ta-181 Stable
Ta-182 114.43 days