identify 2 changes of state that require energy to be used, and 2 changes of state that require the release of energy

Which subatomic part of the atom (a-c) are involved in chemical bonds and reactions?

Most reactions speed up when - a. the temperature decreases b. equilibrium is achieved c. the concentration of the products increases d. the reactant is in small pieces.

What happens when an acid reacts with a metal such as magnesium?

Tom wanted to test his hypothesis that plants grow better at room temperature then in cold temperatures. He placed an ivy plant in the refrigerator, which had no light source. He also placed a spider plant in the window in his room.

The relationship between pressure and volume, when moles and temperature of a gas are held constant, is: PV = k. We could say then, that: If the volume of the gas is doubled, the pressure also doubles.

Hear flows from water in one container to another. What difference between the two samples of water causes heat to flow?

How does a combustion reaction happen and how can we prevent a combustion reaction from happening?

Determine the molecular weight of H2O. 18 g 18.0 g 18.01 g 18.016 g

Nonmetals gain electrons under certain conditions to attain a noble-gas electron configuration. how many electrons must be gained by the element c?

Which of these is a mixture? A. carbon b. oxygen c. air d. Carbon Dioxide