What is the evidence of a chemical reaction when the fireworks go off

Of the reactions below, which one is a double-replacement reaction? A. NH4Cl - > NH3 + HCl B. 2 Mg + O2 - > 2 MgO C. 2 N2 + 3 H2 - > 2 NH3 D. Cd (NO3) 2 + Na2S - > CdS + 2 NaNO3

The main function of the circulatory system (at least a paragraph) !

Which pair of atoms has the highest electronegativity difference? ca, f, h, p, na

Which of the following two conditions will favor a spontaneous reaction? (A) An increase in entropy and a decrease in enthalpy. (B) An increase in both entropy and in enthalpy. (C) A decrease in entropy and a decrease in enthalpy.

What element is represented by the electron configuration [ar]4s23d8?

6. Which atomic particle has a positive (+) charge?

One reason ionic compounds do not dissolve well in nonpolar solvents is that ___. a. ion-solvent interactions are not strong enough to solvate the ions in solution. b.

Muscles undergo fermentation when no carbon dioxide is available. no oxygen is available. no pyruvate is available. no water is available. no atp is available.

Which of the following is evidence of a chemical change? phase change the formation of a gas mass change change in surface area

Spasmolytics can be used to treat