Why does radiation decrease over time? A. As each normal atom decays into a radioactive atom, there are less
normal atoms left to decay.
B. Radioactive particles have a similar charge and as time goes on they
repel each other away.
C. Radiation occurs randomly and as more atoms decay there are less left
to spontaneously decay.
D. Radiation is derived from the concentration of radioactive atoms and the
concentration decreases as radioactive particles are emitted.

Afamily is one another name for a group on the table of elements.

)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.

When a beta particle is emitted, the mass number of the nucleus a. decreases by one b. increases by one c. remains the same d. decreases by two