If originally there were X atoms of radioactive isotope present and now there are only X/16 atoms, how many half-lives have elapsed?
A) 4
B) 1
C) 2
D) 3
A
You might also like to view...
Which one of the following is not one of the four major features of the solar system?
A. Large bodies in the solar system have orderly motions. B. Planets fall into two major categories (terrestrial and jovian). C. Several exceptions to the general trends stand out. D. Swarms of asteroids and comets populate the solar system. E. The solar system contains eight planets plus dwarf planets (such as Ceres, Pluto, and Eris).
A clerk can lift containers a vertical distance of 1 m, or roll them up a 2-m-long ramp to the same elevation. With the ramp, the applied force needed is
A) half as much. B) twice as much. C) the same.
A figure skater on ice with arms extended, spins at a rate of 3.5 rev/s. After he draws his arms in, he spins at 6.0 rev/s. By what factor does the skater's kinetic energy change when he draws his arms in?
a. 2.4 b. 1.7 c. 0.58 d. 0.12
A property of electromagnetic waves that makes them different than other kinds of waves such as sound or water waves is that
A. they do not require a medium to propagate through. B. they are transverse waves. C. their speed can change when moving in different media. D. they have many possible wavelengths.