A certain radioactive isotope placed near a Geiger counter registers 160 counts per minute. Eight hours later, the counter registers 10 counts per minute. What is the half-life of the isotope?

A) 8 hours
B) 6 hours
C) 4 hours
D) 2 hours
E) none of the above


Answer: D

Physics & Space Science

You might also like to view...

As a block slides down a frictionless incline, which of the following statements is true?

a. Both its speed and acceleration increase. b. Its speed increases and its acceleration remains constant. c. Its speed and acceleration remain constant. d. Its speed increases and its acceleration decreases. Both its speed and acceleration decrease.

Physics & Space Science

A planet is detected via the Doppler technique. The repeating pattern of the stellar motion tells us

A) the planet's size. B) the planet's mass. C) the planet's density. D) the orbital period of the planet. E) the orbital eccentricity of the planet.

Physics & Space Science

In an AC circuit, the ratio of average current to maximum current is:

a. zero. b. 0.5. c. 0.707. d. 1.0.

Physics & Space Science

We know that any body more dense than water will sink in water. Why?

What will be an ideal response?

Physics & Space Science