calculate the number of molecules in 1.5 moles of hydrogen chloride (H=1,O=16,S=32,Cl=35.5.Avogadro's constant=6.02×10^23)

Which of these properties, used alone, would be least useful in identifying most minerals? a. color b. luster c. streak d. density

Describe the difference between a. a hypothesis and a theory and b. an observation and an experiment.

Apiece of copper has a temperature of 75.6 0c. when the metal is placed in 100.0 grams of water at 19.1 0c, the temperature rises by 5.5 0c. what is the mass of the metal?