What is released when an excited electron returns to a lower energy state?

Comment on whether each of the following is a homogeneous mixture or a heterogeneous mixture: (a) air in a closed bottle, (b) air over New York City.

What is the concentration of fecl3 in a solution prepared by dissolving 10.0 g of fecl3 in enough water to make 275 ml of solution?

Calculate the hydronium ion concentration in an aqueous solution with a ph of 9.85 at 25°c.

Describe what is happening to the density of the aqueos solution as salt is being added

If the iodate ion has the formula io3¯, what is the name for the acid with the formula hio4?

The organisms living together in a community are interdependent upon one another. Look at the food web below. In which of the following ways is a puffin dependent upon salmon? A. Puffins have a commensalistic relationship with salmon. B.

2) Which of the following is a true statement? A: All the atoms of an element must be identical. B: Compounds may be separated by physical means. C: Mixtures may not be separated. D: Homogeneous is one type of compound.

How to tell the difference between ionic and covalent bonding?

The combustion of propane may be described by the chemical equation C3H8 (g) + 5O2 (g) ⟶3CO2 (g) + 4H2O (g) C3H8 (g) + 5O2 (g) ⟶3CO2 (g) + 4H2O (g) How many grams of O2 (g) O2 (g) are needed to completely burn 83.3 g C3H8 (g) ?

Was the relationship among temperature, heat, and thermal energy?