A radioactive isotope has a half-life of one month. At the end of ...

[xroflmao]

A radioactive isotope has a half-life of one month. At the end of one month, the amount of the original isotope still remaining is
 
  1) none,
  2) one-quarter,
  3) one-half,
  4) three-fourths,
 
  and at the end of two months, the amount of original isotope remaining is
  5) none.
  6) one-fourth.
  7) one-half.
  8) three-fourths.

Question 2

A new theory conforms to the Correspondence Principle when it
 
  1) successfully accounts for the verified results of the old theory.
  2) corresponds to all theories of nature.
  3) states the essence of the old theory, but in an up-to-date way.
  4) successfully ties two or more theories together.
 
  The Correspondence Principle is applicable
  5) principally at the atomic level.
  6) in all realms of physics.
  7) for all good theory, scientific or otherwise.

[Carissamariew]

Answer to Question 1

Answer: 3, 6

Answer to Question 2

Answer: 1, 7

[xroflmao]

Excellent

[atrochim]

TYSM