What is the half‑life of an isotope that decays to 6.25% of its original activity in 51.1 h?

The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?

Consider the following reactions. (note: (s) = solid, (l) = liquid, and (g) = gas.) mg(s) + ½o2(g) → mgo(s) + 146 kcal/mole h2(g) + ½o2(g) → h2o(g), δh = -57.82 kcal/mole what type of reaction is represented by the previous two examples?

What is the molar mass of ca(cio4)2