Which of the following does not happen during a chemical change?

Mass is gained.

New compounds are formed.

Old compounds are broken down.

Bonds are broken.

The system that shows a decrease in entropy (disorder) is

K forms the compound K2O, which is an ionic compound that is brittle. Identify another element, M, that is likely to form a brittle, ionic compound with the formula M2O. Justify your answer in terms of periodic trends.

What kind of atmosphere does a gas giant have?

A balloon is filled to a volume of 1.50 L with 3.00 moles of gas at 25 °C. With pressure and temperature held constant, what will be the volume of the balloon if 0.20 moles of gas are added?

Which of the following is a combustion reaction? 2AgNO3 + H2S → Ag2S + 2NHO3 2H2O → 2H2 + O2 4Fe + 3O2 → 2Fe2O3 2Al + N2 → 2AIN

Student B pushed on a cart against the wall with 500 N of force. The cart didn't move. How do u explain what happened?

What is unique about the way that transition metals form compounds? a. They don't form compounds c. They can form bonds with the electrons in the two outer-most shells b. They are the most reactive d. They can donate all of their electrons

What prompted rutherford to do the alpha particle scattering experiment?

How many moles of hydrogen would be required to produce 5.0 mol of water?

What is the biggest difference between an exothermic and endothermic process? A. The direction of energy flow. B. The amount of energy transferred. C. The type of energy being transferred. D. The speed with which energy is transferred.