What was the commonality between Becquerel and the Curies in terms of their work? polonium radium uranium cesium

Which of the following signs of a chemical reaction are observed in the reaction of potassium with water? precipitate formed temperature change smell produced gas produced color change

At stp, which substance is the best conductor of electricity? a. nitrogen b. neon c. sulfur d. silver

A0.100-kilogram apple hangs in a tree 1.50 meter above the ground. ignore frictional effects, the total mechanical energy of the apples is