What is the ultimate source for naturally occurring carbon-14?
A) Cosmic ray collisions and neutron capture involving nitrogen
B) Dissolution of carbonate rocks
C) Decay of unstable parent isotopes to create a stable carbon-14
D) Volcanic eruption and emission of greenhouse gases
Answer: A
You might also like to view...
The most abundant rock type deposited during the Kaskaskian sequence was ____________________. Fill in the blank(s) with the appropriate word(s)
Rachel Carson's book Silent Spring primarily focuses on the environmental problems associated with ________
A) overpopulation B) deforestation C) aquifer depletion D) loss of biodiversity E) pesticide toxicity
Permanent damage to the ears begins after prolonged exposure to ____ decibels.
A. 46 B. 85 C. 25 D. 142 E. 182
Which of the following acts through a secondary messenger?
A) epinephrine B) glucagon C) luteinizing hormone D) all of these