Asample of thorium-234 has a half life of 25 days. will the thorium undergo rafioacrive decay and be completely gone in 100 days? explain your reasoning and show your work.

Who is better, messi or cristiano, i need this for a chemistry class. asap

Aconcentrated solution of ammonia is 14.8m and has a density of 0.899g/l. what is the concentration of ammonia in this solution in weight percent (%w/w)?

)benzene and toluene form nearly ideal solutions. consider an equimolar solution of benzene and toluene. at 20 °c the vapour pressures of pure benzene and toluene are 9.9 kpa and 2.9 kpa, respectively. the solution is boiled by reducing the external pressure below the vapour pressure. calculate (i) the pressure when boiling begins, (ii) the composition of each component in the vapour, and (iii) the vapour pressure when only a few drops of liquid remain. assume that the rate of vaporization is low enough for the temperature to remain constant at 20 °c.