SeCl6 + O2 --> SeO2 + 3Cl2 what type of equation is this???

Write the symbol for every chemical element that has atomic number greater than 3 and atomic mass less than 12.0 u.

Which piece of equipment would me most useful for measuring the volume of some water? a. pan balance b. graduated cylinder c. tweezers d. flask quick

Explain the relationship between forward and backward reactions in equilibrium, and predict how changing the amount of a reactant (creating a tension) will affect that relationship.