Which of the following is a physical change

A copper roof changing colors from orange to green

Sawing a piece of wood in half

Rust forming on an iron fence

Burning a piece of wood

Find the rms speed of the molecules of a sample of n2 (diatomic nitrogen) gas at a temperature of 34.3°c.

Copper has two naturally occurring isotopes, 63cu (isotopic mass 62.9296 amu) and 65cu (isotopic mass 64.9278 amu). of copper has an atomic mass of 63.546 amu, what is the percent abundance of each isotope

What kind of chemical reaction takes place when a firework explodes

Dillon is conducting a survey about whether or not people like a traffic law that is being passed. Can he publish his findings as a scientific study because he collected information? Yes, because his information is objective.

What is the true ratio of atoms in a molecule or formula unit called

How has earth change during our current era?

What are the phase transitions in which heat energy is gained?

A cylinder contains 4.0 g of nitrogen gas. A piston compresses the gas to half its initial volume. Afterward, by what factor has the mass density of the gas increased?

The balanced equation below represents the reaction between magnesium metal and hydrochloric acid to produce aqueous magnesium chloride and hydrogen gas. Mg (s) + 2HCl (aq) = = > MgCl2 (aq) + H2 (g) A piece of Mg (s) has a volume of 0.

What is the molarity of a solution prepared by dissolving 33.4 g of sodium chloride in some water and then diluting the solution to a volume of 300.00 mL?