How can a half-life be used to tell the age of a sample? A) ...

[bio_gurl]

How can a half-life be used to tell the age of a sample?
 
  A) The half-life of an isotope is constant.
  B) The amount of radioactive form depends on the amount of radiation in the surroundings.
  C) The ratio between the radioactive form and the stable form depends on the archaeological record.
  D) The ratio between the radioactive form and stable form varies regularly with time.
  E) both C and D

Question 2

When a beam of light, originally traveling in air, enters a piece of glass having an index of refraction of 3/2, its wavelength
 
  A) increases by a factor of 3/2.
  B) is reduced to 2/3 its original value.
  C) is unaffected.

[ApricotDream]

Answer to Question 1

Answer: D

Answer to Question 2

B

[bio_gurl]

Gracias!

[Dominic]

TYSM