Calculate the speed of a marble that rolls 9 cm in 4 seconds

Your roll: experienced electron speech is adressed to: a new "freshman class" of electrons job: write a speech task: you are to pretend that you are giving a speech to a new group of electrons. be sure to mention their placement in an atom, their charge, and their role in chemical bonding (ionic and covalent) be specific!

Sulfuric acid (a component of acid rain) reacts with limestone (calcium carbonate) to produce calcium sulfate and carbon dioxide. this damages buildings and statues made of limestone. which solution of sulfuric acid will damage these structures more quickly? a. 0.001% b. 0.005% c. 0.010% d. 0.015%

Compare and contrast physical changes with chemical changes.