Which of the following is NOT an example of a physical change?

a. the shaping of a gold bar

b. the explosion of fireworks

c. the melting of a Popsicle

d. the sanding of a piece of wood

Which of the following is the strongest acid? HCl, H2S, Cl2, H2O

Calculate the enthalpy of the reaction 2NO (g) + O2 (g) →2NO2 (g) given the following reactions and enthalpies of formation: 12N2 (g) + O2 (g) →NO2 (g), ΔfH∘A=33.2 kJ mol-1 12N2 (g) + 12O2 (g) →NO (g), ΔfH∘B=90.2 kJ mol-1

Explain why certain parts of the Earth are more prone to earthquakes or volcanoes.

Mason compare the properties of two compounds magnesium oxide is an ionic compound and hydrogen peroxide is not an ionic compound there for both compounds most likely

Can you determine the molecular formula of a substance from its percent composition

What factors can make atoms unstable

Nitrogen (N), oxygen (O), chlorine (Cl), neon (Ne), and argon (Ar) are all elements that occur as a gas at room temperature (20°C). Using the periodic table, which pair of gases has the most similar properties?

what will be the new volume of a 250mL sample of gas at 300 k and 1 atm if heated to 350 k at 1 atm law use:

Which statement describes the chemical property of oxygen

The reaction CH3NC? CH3CN is called an isomerization reaction andinvolves the breaking of a C-N bond and subsequent formation of a C-C bond-the reactant andproduct have the same molecular formulas and so are isomers.