How do you know when a chemical reaction has taken place?

The thermal energy that flows from one substance to another when the substances differ in temperature.

The enthalpy of combustion of acetylene C2H2 is described by C2H2 (g) + (5/2) O2 (g) →2CO2 (g) + H2O (l),  H rxn = - 1299 kJ/mol.

Why do u see only one side of the moon from earth? a. the moon does not rotate b. the moon takes longer to rotate than to revolve around earth c. the moon takes less time to rotate than to revolve around earth d.

Witch of these is a mixture? A. calcium B. carbon dioxide C. salt water D. potassium

The structure of the atom On the basis of Rutherford's experimental observations, which of the following statements describes the structure of the atom according to Rutherford's atomic model? Check all that apply. A.

Major geological events that occur when plates shift suddenly and released stored energy: A. Volcanic eruptions B. Earthquakes C. Antarctic plate D. Spreading ridges

How does a salt bridge improve a battery

Hat information is needed to determine the energy of an electron in a many-electron atom?

Write the formulas for the following compounds: (a) copper (l) cyanide, (b) strontium chlorite, (c) perbromic acid, (d) hydroiodic acid, (e) disodium ammonium phosphate, (f) potassium dihydrogen phosphate, (g) iodine heptafluoride, (h)

Name a complex salt used in silver-playing.