This topic contains a solution. Click here to go to the answer

Author Question: Elements above uranium in the periodic table do not exist in any appreciable amounts in nature ... (Read 49 times)

karlynnae

  • Hero Member
  • *****
  • Posts: 599
Elements above uranium in the periodic table do not exist in any appreciable amounts in nature because they have short half-lives.
 
  Yet there are several elements below uranium in atomic number with equally short half-lives that do exist in appreciable amounts in nature. How can you account for this?
  A) These are isotopes formed by living bodies.
  B) These isotopes were placed in nature by the testing of nuclear bombs.
  C) These isotopes were formed from the fusion of even smaller isotopes.
  D) These isotopes result from the radioactive decay of uranium.

Question 2

When a beam of light that is traveling in glass strikes an air boundary at the surface of the glass, there is
 
  A) a 90 phase change in the reflected beam.
  B) no phase change in the reflected beam.
  C) a 180 phase change in the reflected beam.
  D) a 60 phase change in the reflected beam.
  E) a 45 phase change in the reflected beam.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

jamesnevil303

  • Sr. Member
  • ****
  • Posts: 337
Answer to Question 1

Answer: D

Answer to Question 2

B




karlynnae

  • Member
  • Posts: 599
Reply 2 on: Jul 29, 2018
Great answer, keep it coming :)


Liddy

  • Member
  • Posts: 342
Reply 3 on: Yesterday
YES! Correct, THANKS for helping me on my review

 

Did you know?

As the western states of America were settled, pioneers often had to drink rancid water from ponds and other sources. This often resulted in chronic diarrhea, causing many cases of dehydration and death that could have been avoided if clean water had been available.

Did you know?

Fungal nail infections account for up to 30% of all skin infections. They affect 5% of the general population—mostly people over the age of 70.

Did you know?

The ratio of hydrogen atoms to oxygen in water (H2O) is 2:1.

Did you know?

Aspirin is the most widely used drug in the world. It has even been recognized as such by the Guinness Book of World Records.

Did you know?

The average older adult in the United States takes five prescription drugs per day. Half of these drugs contain a sedative. Alcohol should therefore be avoided by most senior citizens because of the dangerous interactions between alcohol and sedatives.

For a complete list of videos, visit our video library