The isotope 208tl undergoes î² decay with a half-life of 3.1 min.
(a) what isotope is produced by the decay?
(b) how long will it take for 99.0% of a sample of pure 208tl to decay?
(c) what percentage of a sample of pure 208tl remains un-decayed after 1.0 h?

How does chemistry affect our world? a. chemicals makes our world more polluted. b. chemicals keeps us healthy. c. chemicals can or hurt our world. d. chemicals make our world safe to live in.

Why is the vapor pressure of a warm lake higher than the vapor pressure of a cold lake? o a. warm water has a greater heat of vaporization. ob. warm water evaporates more quickly. cool water evaporates more quickly. od. cool water has a greater heat of vaporization.

The reactions shown here can be combined to make the overall reaction c(s) + h2o(g) ⇌ co(g) + h2(g) by reversing some and/or dividing all the coefficients by a number. a. c(s) + o2(g) → co2(g) k=1.363×10^69 b. 2 h2(g) + o2(g) → 2 h2o(g) k=1.389×10^80 c. 2co(g) + o2 (g) → 2 co2(g) k=1.477×10^90