What does variable mean

The combustion of hydrogen gas in oxygen, is it an endothermic or exothermic process? Write a chemical reaction for this process

A chemical equation can be used to solve stoichiometry problems provided that it A. indicates only the forward reaction and not the reverse. B. indicates that reactants are in the gas phase and are not solids or liquids. C.

If you place a crystal substance on a tabletop, return to view it after some time passes, and find it as a powdered substance, which of the following processes most likely took effect? A. Efflorescence B. Distillation

Assume that you measured exactly 2.0 mL of the sodium chloride solution into a small test tube. How many moles of sodium chloride are in the tube?

Which compound is a nonelectrolyte? copper chloride carbon tetrachloride sodium bromide magnesium sulfate?

The Carbon family element in period 4

Generally speaking, which group would have the lowest electronegativity values in a period? Group 1 Group 3 Group 14 Group 17

Radioactive decay is a spontaneous process. occurs when an unstable nucleus loses energy. does not require any input of energy. all of the above

What effect does a hypotonic solution have on a red blood cell?

A negative △H means an exothermic reaction. True False