I.M.S. SCIENCE              NAME: _____________PERIOD: ___ DATE:_____

Detecting Radiation Lab: Student Activity.

Materials: Clear plastic jar with a tight lid (peanut butter jar), Blotter paper, eyedropper, radium salt source, dry ice, flat black paint, alcohol, flashlight, strong bar magnet, IR thermometer.

(See the figure 1) Note take IR temperature readings as lab continues.

1. Paint the inside of the plastic jar flat black.
2. Place the radium salt source in bottom of jar after wrapping in plastic wrap.
   (old luminous clock or watch face, or a gas mantle)
3. Wet the blotter paper with alcohol and place around the inside of the plastic jar.                                                                 Blotter IR temperature= _____ Deg C.
4. Wet the inside bottom of the plastic jar with an eyedropper with a few drops of alcohol, then put the lid on tightly and place on top of a slab of dry ice.  

                                                                           Dry Ice IR temperature= _____ Deg C.

5. Let the jar cool for about two minutes then take
                                                               Dry Ice IR temperature#2= _____ Deg C.
6. Darken the room and illuminate with a flashlight from the side of the jar. (tracks will begin to appear when the chamber has cooled enough)
7. When the tracks begin to appear take the
                                                                Dry Ice IR temperature#3= _____ Deg C.
8. Alpha particles are one-half inch long and quite sharp. Beta particles have longer thinner tracks. Gamma particles have twisting, circling tracks that are very faint and difficult to see.
9. The air layer near the bottom of the jar is supersaturated with alcohol vapor. Because there is more vapor in the air than usual at the low temperature the gas will form liquid droplets whenever it is disturbed. Dust in the jar will cause mist to fall to the bottom of the jar during the first half-hour.

      The tracks formed by the radiation appear to be white lines in the cloud. As  

      the radiation passes through, it knocks electrons out of the atoms in the air.

      The alcohol vapor then condenses on the charged particles, forming little

      storms along the path.

10. Hold the north end of a magnet next to the jar, observe its effect.
11. Wrap the mantles in a sheet of paper and observe the results.