How did Becquerel's results allow him to conclude that something other than phosphorescence was
causing the film to darken?
His results showed that uranium not exposed to light still produced the same effect as uranium
exposed to light.
His results showed that any rock will darken film
His results showed that only uranium exposed to light produced the darkening effect on the film,

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Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? a. the balloons both rise. the cold balloon is larger than the warm balloon. b. the balloons rise at the same rate. both balloons are the same size. c. the warm balloon expands and rises. the cold balloon shrinks and sinks. d. the cold balloon expands and rises. the warm balloon shrinks and sinks.

What is the ima of the 1 st class lever in the graphic given? 2 3 0.5