How many Na + ions are in 3.0 moles of Na2O?

Which of the following is a true statement about energy? a. energy can be created and destroyed. b. energy is never created nor destroyed. c. energy is easily created, but cannot be destroyed. d. energy cannot be converted from one form to another.

8 most common elements in earths crust

Which action will slow down the rate of a reaction A. Increasing the concentration of the reactants B. Adding a catalyst to the reaction C. Raising the temperature of the reactants D. Decreasing surface area of a solid reactant

A chemist determined by measurements that 0.050 moles of aluminum participated in a chemical reaction. Calculate the mass of aluminum that participated in the chemical reaction. Be sure your answer has the correct number of significant digits.

As the temperature of a sample of matter is increased, what happens to the average kinetic energy of the particles in the sample? A. It decreases. B. It increases. C. It does not change.

Much of life on Earth is based in aquatic biomes. What property of water allows life to survive in liquid water?

A neutral atom of beryllium (Be) has an average mass of 9 amu and 4 electrons. How many neutrons does it have? 13 9 5 4

Calculate the maximum mass of carbon dioxide that could be obtained by adding excess hydrochloric acid to 15 g of calcium carbonate.

True or false: during dry weather, the water level in a small pond drops because of runoff.

Bradley hit a baseball with a bat. The baseball then hit a window and caused the window to break. Where did the energy that broke the window come from?