Question

QUESTION 10

1. A(n) ____________ is a variety of an element with the same number of protons and electrons as the other types of the element but a different number of neutrons.

1 points   

QUESTION 11

1. Isotope fractionation occurs when a physical or chemical process causes the relative abundance of the isotopes in a sample of matter to change based on the count of the isotopes.

   True

   False

1 points   

QUESTION 12

1. Why does evaporation cause water vapor to be enriched in light isotopes (H₂¹⁶O) in comparison to liquid water?

   	a.	H216O is condensed more readily
   	b.	H216O undergoes radioactive decay
   	c.	H216O bonds to minerals in water less readily
   	d.	H216O is lighter than H218O

1 points   

QUESTION 13

1. Choose the 2 reasons some atoms are radioactive.

   	a.	the nucleus itself is too large
   	b.	the nucleus itself is too small
   	c.	the number of additional neutrons of an isotope is too large
   	d.	atomic numbers < 83
   	e.	the number of additional neutrons of an isotope is too small

2 points   

QUESTION 14

1. The _____ of a radioisotope is the amount of time needed for 1/2 of its atoms to transform one isotope to another.

1 points   

QUESTION 15

1. You are an ice core researcher, and are examining a sequence of  δ¹⁸O measurements obtained from an ice core from Greenland. The measurements are from a section of the core that is not near the surface. The measurements show an increase of  δ¹⁸O in the ice, from more negative values at a greater depth (from the older layers) to less negative values above that (from the younger layers). Given what you know about the way oxygen isotopes in polar ice cores vary in response to atmospheric temperature changes, what do you think happened to the atmospheric temperature during this interval? Choose the correct answer with the correct reason.

   	a.	The temperature did not change. This is known because when the climate stays the same there is not change in evaporation of the heavy isotope and thus there will be the same amount of the heavy isotope that can precipitate. The ice core will then record this constant amount of the heavy isotope.
   	b.	It got warmer. This is known because in a warmer climate there is an increase in evaporation of the light isotope and thus there will be more of the light isotope that can precipitate. The ice core will then record this increase in the amount of the light isotope.
   	c.	It got warmer. This is known because in a warmer climate there is an increase in evaporation of the heavy isotope and thus there will be more of the heavy isotope that can precipitate. The ice core will then record this increase in the amount of the heavy isotope.
   	d.	It got colder. This is known because in a colder climate there is an increase in evaporation of the heavy isotope and thus there will be more of the heavy isotope that can precipitate. The ice core will then record this increase in the amount of the heavy isotope.

1 points   

QUESTION 16

1. Which of the following 3 environmental conditions can be deduced by analysis of ice cores?

   	a.	volcanic activity
   	b.	sea level rise
   	c.	Earth's temperature
   	d.	CO2 level
   	e.	frequency of hurricanes
   	f.	biological carbon pump

3 points   

QUESTION 17

1. Match the characteristic of the atmosphere to the correct geologic eon.

   -       A.       B.       C.    Hadean       -       A.       B.       C.    Archean       -       A.       B.       C.    Proterozoic

   A. Two possibilities. First possibility is that it was very hot with high volcanism. Second possibility is that it wasn't too hot and liquid water was present. In both possibilities, there was planetary bombardment by asteroids. B. Oxygen levels started building in the atmosphere as a result of the development of photosynthesis, and once iron in the ocean was oxidized. There were multiple glaciations of varying durations. C. The atmosphere had high levels of greenhouse gases, temperatures near current levels, and no oxygen.

3 points   

QUESTION 18

1. What has been the dominant characteristic of Earth's temperature over the past two million years, but before modern humans arose?

   	a.	repeated glaciations and interglacials
   	b.	snowball Earth
   	c.	warmer than today's temperature
   	d.	about the same as today's temperature

1 points   

QUESTION 19

1. What is the geological eon, era, period, and epoch in which we are living?

   	a.	the Proterozoic Eon, the Cenozoic Era, the Neogene Period, and the Holocene Epoch
   	b.	the Phanerozoic Eon, the Cenozoic Era, the Quaternary Period, and the Holocene Epoch
   	c.	the Phanerozoic Eon, the Mesozoic Era, the Quaternary Period, and the Eocene Epoch
   	d.	the Phanerozoic Eon, the Cenozoic Era, the Paleogene Period, and the Miocene Epoch

1 points   

QUESTION 20

1. The Younger Dryas was

   	a.	a brief period of dry climate that occurred about 12,000 years ago.
   	b.	a long period of dry climate that occurred about 300 Ma.
   	c.	a brief period of cold climate that occurred about 12,000 years ago.
   	d.	a long period of cold climate that occurred about 300 Ma.

Answer 1

Answer - 10)

Isotopes is a variety of an element with the same number of protons and electrons as the other types of the element but a different number of neutrons

In other words it can be described as different variants of a particular chemical elements differing in neutron number. For example Carbon 12 & Carbon 14 are isotopes of carbon with 6 & 8 neutrons respectively.

Note :- As per HomeworkLib policy i am allowed to answer only the first question.

Hope this helps you !!!