When using nitrogen in repairing a sealed refrigeration system the nitrogen tank should always be equipped with a: ?

Nacidified solution was electrolyzed using copper electrodes. a constant current of 1.18 a caused the anode to lose 0.584 g after 1.52 ✕ 103 s. given that the charge of an electron is 1.6022 ✕ 10−19 c, calculate avogadro's number. assume that copper is oxidized to cu2+ ions.

What is friction? how does it affect the motion of an object?

Why does lightning travel from clouds to the ground?