List four common signs that a chemical reaction has occurred.

What is a reliable source?

When molecules slow down, they expand. A True B False

What are two features used to describe matter

The volume and amount of gas are constant in a tire. The initial pressure and temperature are 0.8 atm and 296 K. At what temperature (in K) will the gas in the tire have a pressure of 2.2 atm?

Unlike the methods of early scientists, how did Sir Francis Bacon believe basic laws of science should be determined? A. by using inductive reasoning based on empirical evidence B. by using inductive reasoning based on a few basic truths C.

Hydrochloric acid is purchased in 12 molar concentrations. If I needed 200 ml of 2.0 molar HCl, how many milliliters of the concentrated solution would I need

Which of the following represents a chemical change? Bending a wire Freezing of water Fireworks exploding Melting of a wax candle

5.00 L of a gas is collected at 100K and then allowed to expand to 20.0 L. What must the new temperature be in order to maintain the same pressure? A. 400 °C B. 127 °C C. 223 °C D. 627°C

Before the initial explosion was the matter hot or cold

Which of the following atoms has seven valence electrons? chlorine (Cl) nitrogen (N) manganese (Mn) oxygen (O)