The half-life of 19N is 0.42 s. What is the decay constant for ...

[dejastew]

The half-life of 19N is 0.42 s. What is the decay constant for this isotope?
 a. 1.7  1011 Ci
  b. 1.7 s1
  c. 1.1 s1
  d. The decay constant is not defined for a half-life of less than one second.

Question 2

The half-life of radioactive Technetium-99 is 6.0 hours. Find the number of 99Tc nuclei necessary to produce a sample of activity 18 Ci. (1 Ci = 3.7  1010 decays/second)
 a. 1.2  109
  c. 8.0  108
  b. 3.4  1011
  d. 2.1  1010

[moormoney]

Answer to Question 1

B

Answer to Question 2

D

[dejastew]

Excellent

[xoxo123]

Thanks for the timely response, appreciate it