Which of these indicate that a chemical reaction has occurred?

A.) Formation of a gas.

B.) Boiling of a substance.

C.) Melting of a substance.

D.) Freezing of a substance.

How much heat (energy) would be required to raise 20 grams of an unknown substance from 23 degrees Celsius to 33 degrees Celsius

Why are H2S, mercaptans, sulphur compounds and salt removed from the crude oils?

Examine the information. A Magellanic penguin is at an initial position of 4 m and waddles to a position of 8 m in 8 s. What is the penguin's average velocity? -4 m/s 4 m/s 0.5 m/s 2 m/s

Why arent the jaguars and sloths growing and thriving?

Which of the following is the best example of erosion? A. Sediment piling up at the mouth of a river B. Plant roots growing through concrete and splitting it C. Waves carrying sand away from a beach D.

What is the molecular geometry, or shape, of beryllium chloride (becl2) ?

What is the best category for nf3? 1. amphoteric ion 2. lewis acid 3. salt 4. bronsted-lowry acid 5. arrhenius acid 6. arrhenius base 7. lewis base 8. weak electrolyte?

100 g = ___hg for science

A real gas behaves more like an ideal gas when the gas molecules are

How many moles are in 12.5 g of H2O