What does the the release or absorption of energy indicate?

A. Physical Change

B. Chemical Change

C. Physical and chemical changes

D. Neither physical nor chemical changes

What type of hybridization is needed to explain why ethyne, C2H2, is linear?

What would happen if an organ in the digestive system stopped working

Object a at 40 degrees C and object b at 80 degrees C are placed in contact with each other which statement descibes the heat flow between the objects

A possible mechanism for the overall reaction represented above is the following. NO (g) + NO (g) → N2O2 (g) slow N2O2 (g) + O2 (g) → 2NO2 (g) fast Which of the following rate expressions agrees best with this possible mechanism?

The average cup of coffee contains about 125 mg of caffeine, C8H10N4O2. Caffeine is also found in tea, colas, and headache remedies. What is the mass (in grams) of one molecule of caffeine?

How was helium first discovered?

When is alpha particle emission most likely to occur? A. When the nucleus has more than 83 protons. B. When the ratio of neutrons to protons in the nucleus is too high to be stable. C. When the nucleus has a mass of more than 83 amu. D.

Researchers used a combustion method to analyze a compound used as an antiknock additive in gasoline. A 9.394 mg sample of the compound yielded 31.154 mg of carbon dioxide and 7.977 mg of water in the combustion.

The formula for binary ionic compound formed between cesium and fluorine

If the mass of a material is 76 grams and the volume of the material is 16 cm3, what would the density of the material be? g/cm3