What is the half-life of a radioactive element?
a. Half the amount of time it takes the element to decay.
b. The amount of time in which half the quantity of the element will decay.
c. One-half curie of the element.
d. The inverse of the number of decays per second from a sample, expressed in units of time.
e. Half of the amount of the element needed for decay to proceed.
b
You might also like to view...
This image shows the velocity of gas moving toward or away from us on the Sun's surface, as measured through Doppler shifts; the key indicates the measured velocity, with negative velocities indicating gas moving toward us and positive velocities away from us. What do the small-scale changes in the shading represent in this map?
A) vibrations of gas moving up or down at the solar surface B) variations in the altitude of the solar surface C) variations in the temperature of the photosphere D) Nothing; this is an artist's rendering of the sun.
The wave function of an electron in a rigid box (infinite well) is shown in the figure. If the electron energy 98.0 eV, what is the energy of the electron's ground state? (mel = 9.11 × 10-31 kg)
A) 6.13 eV B) 3.92 eV C) 10.9 eV D) 24.5 eV
In the above H-R diagram sketch, which star is a red giant?
A. A B. B C. C D. D E. E
The Voyager probes carry what kind of physical time capsule?
A) a small engraved plaque B) a gold-plated record containing pictures, multilingual greetings and music C) a DVD containing pictures D) these probes do not carry a physical time capsule