In the video about half-life, ra-223 decays to rn-219 by alpha decay with a half-life of 11 days. assuming you start with 160 grams of ra-223, how much would be left after 33 days?

Benzonitrile (c6h5cn) is reduced to two different products depending on the reducing agent used. treatment with lithium aluminum hydride followed by water forms k, which has a molecular ion in its mass spectrum at 107 and the following ir absorptions: 3373, 3290, 3062, 2920, and 1600 cm-1. treatment with a milder reducing agent forms l, which has a molecular ion in its mass spectrum at 106 and the following ir absorptions: 3086, 2850, 2820, 2736, 1703, and 1600 cm-1. l shows fragments in its mass spectrum at m/z = 105 and 77. propose structures for k and l and choose an explanation for how this could be concluded.

The mass of a proton is approximately equal to the mass of

H2o is a single atom of wat true or false?