Of the following, which does not signify a chemical reaction?

1) tarnish

2) release of heat

3) changing state

4) release of gas

For the reaction of nitrogen gas and hydrogen gas to make methane below, what stresses would shift the equilibrium to the left toward the reactants? N2 (g) + 3 H2 (g) ⇌ 2 NH3 (g) + Energy

Gamma, beta and alpha radiation are all alike because: they all have the same mass they all have the same charge they all can be emitted from the nucleus of an atom they all have the same energy

Give the total number of atoms in one formula unit of CaC2O4

Given 1.00 gram of (NH4) 2 CO3, how many grams of this sample would be due to hydrogen?

Which group of elements contains the most reactive metals? iron triad transition metals alkali metals alkaline earth metals

Which of the following are chemicals? A. clothing B. food C. fuels D. all of the above

How many valence electrons are in atom of sulfur?

My sister needs this answered! Donald is creating an experiment to determine if fertilizer affects plant color. He makes this statement: "If each plant receives a different amount of fertilizer, then the plant's color intensity will change.

What would happen to life if earth were in a different location within the solar system

Substance that undergoes a change in a chemical reaction is a. a product c. a reactant. b. a chemical. d. an enzyme.