Janice needs to have a gastro-intestinal study. So she is given 375 mg of radiocontrast dye containing Barium-142. The half-life of Ba-142 is 10.6 minutes and its decay is followed by -ray. After one half -life, of Ba-142 remains . After 31.8 minutes , of Ba-142 remains . After half-lives, 11.7 mg of Ba - 142 remains . After minutes , 0.366 mg of Ba - 142 remains. Finally, after approximately 3.5 hours - half-lives , only 0.000358 mg remains . The dye is no longer visible to the Xray and Janice's study is over .

After one half life, 188mg

46.9 mg of Ba-142

After 5 half lives

After 106 minutes

20 half lives , only 0.000358 mg remains

Hope this helps

chemists can use the electron cloud model to assign electrons to different atomic orbitals. atomic orbitals also explain the patterns in the periodic table

explanation:

in the given question, the partial pressure is calculated by using the ideal gas equation, that is, pv = nrt

here, p is pressure, v is volume = 25 l, n is number of moles = 0.0104 moles, r is gas constant = -0.0821 l.atm / mol.k

t is temperature = 273 k

p = nrt / v

p = (0.0104 mol × 0.0821 l.atm / mol.k × 273 k) / 25 l

= 0.0093 atm