In physical science lab, ben and jerry added small pieces of magnesium to hydrochloric acid. they noticed that bubbles formed, the test tube got hot, and the magnesium disappeared. what is a sign that a chemical reaction has taken place in this experiment?

The pressure, volume, and temperature of a mole of an ideal gas are related by the equation pv = 8.31t, where p is measured in kilopascals, v in liters, and t in kelvins. use differentials to find the approximate change in the pressure if the volume increases from 14 l to 14.6 l and the temperature decreases from 375 k to 370 k. (round the answer to two decimal places.)

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration

Which symbol in the first law of thermodynamics represents the sum of the chemical and thermal energy stored in atoms and molecules? a. q b.w c.v d.u