The isotope, tritium, has a half-life of 12.3 years. Assume we have 10 kg of the substance. How much tritium will be left after 30 years?
a. 0.20 kg
b. 1.8 kg
c. 0.18 kg
d. 1.7 kg
e. 4.1 kg
b
You might also like to view...
What is the wavelength of the emitted photon if an electron in the hydrogen atom makes a transition from the n = 7 state to the n = 2 state?
(c = 3.00 × 108 m/s, h = 6.626 × 10-34 J ? s, 1 eV = 1.60 × 10-19 J) A) 199 nm B) 365 nm C) 4480 nm D) 398 nm E) 796 nm
A particular lightbulb produces 8 J of thermal energy while producing 2 J of radiant energy, and this is its entire energy output during this time. How energy-efficient is this bulb [as a producer of light]?
A) 400% B) 20% C) 25% D) 500% E) 80%
What is a standard candle?
A) an object for which we are likely to know the true luminosity B) an object for which we can easily measure the apparent brightness C) a class of objects in astronomy that all have exactly the same luminosity D) any star for which we know the exact apparent brightness E) a long, tapered candle that lights easily
A region in the Universe where there are almost no galaxies is called a ________.
A. void B. supermassive black hole C. dark nebula D. zone of avoidance