Which of the following is/are true? A. In each period, the atomic numbers increase from left to right.

B. The periods are numbered 1 through 7 on the left-hand side of the periodic table.

C. Elements in the same period have chemical properties which are not all simular.

D. All of the above

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

Ascientist measures the speed of sound in a monatomic gas to be 449 m/s at 20∘c. what is the molar mass of this gas?

How does the value of the equilibrium constant show that a reaction reaches equilibrium very quickly? (a) the equilibrium constant is large. (b) the equilibrium constant is small. (c) the equilibrium constant is zero. (d) the value of the equilibrium constant does not show how quickly a reaction comes to equilibrium.