Which of these is indication that a chemical reaction has occurred?

A. Freezing of a substance

B. Melting of a substance

C. Boiling of a substance

D. Formation of a Preciptate

Do you think it is likely that a major volcanic eruption will occur on the mainland of the United States

Gas molecules are strongly attracted to one another. 1. True 2. False

What is the meaning of ug

It is possible to increase a reaction rate by adding very small amounts of a catalyst, and this is because ... A. The catalyst is used over and over again during the reaction. B. Only a small amount of catalyst is needed to increase temperature. C.

Which of these is a body fossil? A. Dinosaur nest B. Shrimp burrow C. Leaf imprint D. Claw print

What is 1.724 L expressed in cm3?

Consider a three sequentially stepped process named as Process A, Process B and Process C. Input comes into Process A. Output form A goes into Process B. Output from B goes into Process C. Output of C is the final output.

What are elements and how do they differ?

Write the structire of the salt that forms when diethylamine is mixed with hydrochloric acis

The heat of combustion of propane, C3H8, is 2220 kJ/mol. The specific heat of copper is 0.385 J/g°C. How many grams of propane must be burned to raise the temperature of a 10.0 kg block of copper from 25.0°C to 65.