Based on the information gained from the graph above, answer the following: You

Question

Based on the information gained from the graph above, answer the following: You are given a sample of sediment that consists of pebbles and cobbles. If the velocity of water in a river is 500 cm/sec in order to transport this sample of sediment. d. The velocity of the water & the sizes of the sediment are not related to transportation of sediment by a river. A half-life is the amount of time required for half of the existing parent isotopes (radioactive) to decay to daughter isotopes (may be radioactive or nonradioactive). From an original sample of 3000 radioactive parent isotopes, how many parent and daughter isotopes will be present after two half-lives have passed?? a. 1500 parent; 1500 daughter b. 750 parent; 2250 daughter c. 1000 parent; 2000 daughter d. 2250 parent; 750 daughter Which of the following phenomena best illustrates the concept of Earth System interactions and how this is expressed in geologic phenomena? a. Cooling rates of magma in deep intrusions, because the mineral assemblages are general classified within various mineral systems. b. The assemblage of fossils within a given geologic layer, because these are defined by taxonomy which presents a rigorous system for species classification. c. The evolution of landforms, as these are often influenced by relationships between the rock formations and structure with both climate and biological processes. d. None of these, because the Earth Systems concept was discredited as geologists began to understand plate tectonics.

Explanation / Answer

59. d) The velocity of the water and the sizes of the sediment are not related to transportation by a river.

60. One of the most important tools in geology is radioactive decay. By measuring the ratio of parent to daughter atoms in a mineral sample, we can find the time at which a mineral formed. The amount of time it takes for half of an parent isotope to turn into its daughter isotope is called the half-life. If you know the half-life of an isotope, and the amount of parent and daughter atoms present in a sample, you can calculate the age, t, of the sample using
  t= 1/ ln ( 1 + D/N )

where is the decay constant, D is the number of daughter atoms and N is the remaining number of radioactive atoms. This age is an actual measurement of elapsed time, instead of a relative measure (e.g., old, older, oldest); we therefore call time scales based on radioactive decay absolute time scales.

The half-life of an element measures the mean time it takes for half of the parent atoms to decay into daughters but it says nothing about the behaviour of any given atom. Instead, the life-time of any given atom is essentially random; one atom may only last one half-life, whereas another may last several hundred half-lives. The mathematical laws that describe radioactive decay also describe a variety of other natural processes, such as rolling dice, flipping coins or the number of raindrops that hit in a square centimenter. Because of this, sometimes these other processes are used to model the decay process; in the animation shown above, we used a random number generator to determine when each particle would decay.

So, a) 1500 : 1500 daughter.

61. Environmental science studies the interactions between the physical, chemical, and biological components of the environment, including their effects on all types of organisms. Earth science (also known as geoscience), is an inclusive term for all sciences related to Earth (geology, meteorology, oceanography, etc). Although environmental and earth science cover essentially the same material, environmental science places greater emphasis on the biological realm, while earth science places greater emphasis on the physical realm.  
Environmental and earth science study the interactions of four major systems or “spheres”.

So, c) The evolution of landforms, as these are often influenced by relationships betwen the rock formation and teh structure with both climate and biological processes.

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