The decay constant of neptunium-239 is 0.2975 d-1. What are its (a) half-life and (b) mean life?
What will be an ideal response?
Question 2
The distance between two asteroids is 1600 km. How much time does it take for a light signal to go from one asteroid to the other? (c = 3.0 108 m/s)
A) 19 ms
B) 4.5 ms
C) 5.3 ms
D) 13 ms
E) 19 s