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What is the oxidation number of carbon (C) atom in the following compound, CaC2O4?

What is the valence electron configuration of Se (element #34)?

Given that 1 inch (in) = 2.54 cm, 1285 cm2 = ________ in2.

What is the empirical formula of a compound consisting of 85.6% C and 14.4% H by mass?

What is the mass of ZnSO4 (molar mass: 161.47 g/mol) needed to prepare 250.0 mL of 1.80 M ZnSO4 solution?

In general, stronger bond has a _______ bond length and a ________ bond enthalpy.

Calculate the change in the internal energy of a system when it releases 140 J of heat to the surroundings and does 85 J of work on the surroundings at the same time.

What is the ground-state electron configuration of copper (Cu) atom?

When the equation below is properly balanced with the smallest set of whole numbers, the coefficient in front of O2 is __________. NH3 + O2   → NO  +  H2O2  

What is the formula of an oxide of an alkali metal (M)?