The half-life of cobalt-60 is 5.3 years, while that of strontium-90 is about 29 years. Suppose you have samples of both isotopes, and that they initially have the same activity (number of decays per second)
What must be true of the numbers of cobalt-60 and strontium-90 nuclei in these samples? A) There are more strontium-90 than cobalt-60 nuclei.
B) There are equal numbers of cobalt-60 and strontium-90 nuclei.
C) There are more cobalt-60 than strontium-90 nuclei.
D) It is not possible to compare numbers of nuclei without knowing the masses of the samples.
A
You might also like to view...
Discrete radii and energy states of atoms were first explained by electrons circling the atom in an integral number of
A) wave frequencies. B) de Broglie wavelengths. C) diffraction patterns. D) high-speed particles. E) none of the above
An astronaut has landed on another planet and conducts an experiment to determine the acceleration of gravity on that planet. She uses a pendulum 0.640 m long and determines that the period of oscillation is 2.60 s
What is the acceleration of gravity on that planet? A) 4.85 m/s2 B) 1.66 m/s2 C) 3.74 m/s2 D) 2.39 m/s2 E) 9.81 m/s2
People can snorkel down to a depth of roughly one meter. This means that the additional pressure on the air in their lungs is roughly
A. 9800 N. B. 9800 Pa. C. 9800 ATM. D. 19,600 N. E. 19,600 N/m2.
Describe the large-scale structure revealed by the redshift surveys
What will be an ideal response?