Battery Lightbulb
Metal
paper
clips
Wood
Motal noodle
Wire
Why does the bulb light when the needle touches a paper clip?
point
1. convection cells are produced
2. vibrations set up wavelike disturbances
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3. a circuit is completed
4. a phase change occurs

Lab reagent, hypothesis test.a reference solution used as a lab reagent is purported to have a concentration of 5 mg/dl. six samples are taken from this solution and the following concentrations are recorded: (5.32, 4.88, 5.10, 4.73, 5.15, 4.75) mg/dl.these six measurements are assumed to be an srs of all possible measurements from solution.they are also assumed to have a standard deviation of 0.2, a normal distributin, and a mean concentration equal to the true concentration of the solution.carry out a significance test to determine whether these six measurements provide reliable evidence that the true concentration of the solution is actually not 5 mg/dl.