Which formula represents an ionic compound?1) NO2) KCl3) HCl4) CO2

At room temperature what happens to the average kinetic energy of the molecules of a solid, liquid, and a gas

Suppose that some of the compound spilled out of the crucible after it was heated. would that cause the percent by mass of water in the compound determined by the experiment to be too low, too high, or unchanged? briefly explain your answer.

If e is the symbol for an element, which two of the following symbols represent isotopes of the same element? 1. e2. e3. ea.1 and 2c.1 and 4b.3 and 4d.2 and 3