When two substances are mixed and light is produced is it a chemical or physical change?

1. Identify each of the following changes as endothermic, exothermic, or not possible to tell. The matter to keep in perspective is in italics in each case. Explain your decision in each case.

If a substance has a density of 2.82 g/mL, what will be the volume (in mL) of a 5.71 g sample

Which of the following is the best comparison of the density of basalt and granite? Basalt is more dense than granite Granite is more dense than basalt Granite and basalt have equal densities The density of both is variable everywhere

What are two methods for writing a balanced formula

Column chromatography is based on the principle of

What is the most accurate description of compounds?

A researcher wants to test the solubility (property of being dissolved) of salt in water as the temperature of the water increases.

If you have three moles of S2, how many moles of Al2S3 can be produced?

Predict whether each of the following reactions will occur in aqueous solutions. Explain your reasoning in each case. Note: Barium sulfate and silver bromide precipitate in aqueous solutions.

The digestive system is the body system that Text to speech A:A. breaks down food into substances that can be absorbed and used for energy. B:B. gets rid of the remaining solid waste that cannot be absorbed. C:C.