What is the mass of 25.0 mCi of technetium-99m (Tc99m)Tc99m , which has a half-life of 6.00 h?

A single atom of cesium-133 has a mass, in atomic mass units, of 132.90545193 u. Determine a) the mass defect in atomic mass units b) the total binding energy in MeV c) the average binding energy per nucleon Thank you for the help. I appreciate it

Archeologist extracted 179 gm of carbon from an animal bone from an archeological site. The carbon shows an activity of 15 decays/s. (Half-life of 146C = 5730 years, 1 year = 3.156 x 107 seconds, Avogadro's number = 6.02 x 1023 atoms/mol) (A) Total number of atoms in this carbon sample =        . (B) Decay constant of 146C, λ =           . (C) Number of 146C atoms in this sample =          . (D) Activity of 146C at time (t = 0) =            . (E) Age of the animal =

Mantles for gas lanterns contain thorium, because it forms an oxide that can survive being heated to incandescence for long periods of time. Natural thorium is almost 100% 232Th, with a half-life of 1.405 x 10¹0 y. If an average lantern mantle contains 270 mg of thorium, what is its activity (in Bq)? XBq t