What is hydrogen a mixture, element, or compund?

Based on the location of nitrogen (N) on the periodic table how many additional electrons does a nitrogen atom need in its valence shell to satisfy the octect rule when it forms bonds

Which of the following is an example of a physical change? A) grinding coffee beans B) baking a cake C) converting water to hydrogen and oxygen D) digesting a cheeseburger E) burning coal

What is the reduction half-reaction for this redox equation? Ca + Al (NO3) 3 → Al + Ca (NO3) 2

17. A gas tank holds 2785 L of propane, C3H8, at 830. mm Hg. What is the volume of the propane at standard pressure?

Suppose you digested 0.25 g of a copper ore samplein 15 mL of solution. One mL of this solution is transferred to a 10 mL volumetric flask, which is filled to the calibration level. The resulting concentrationwas 0.0087M Cu2+.

5. Identify a suitable method that would be used to separate mixture of the follow [b]Water and ethanol c]Table salt dissolved in water d] iodine and potassium Pul the table below

How much energy is needed to convert 57.3 grams of ice at 0.00°c to water at 75.0°c? specific heat (ice) = 2.10 j/g°c specific heat (water) = 4.18 j/g°c heat of fusion = 333 j/g heat of vaporization = 2258 j/g?

A certain first-order reaction (A→productsA→products) has a rate constant of 9.90*10-3 s-1s-1 at 45 ∘C∘C. How many minutes does it take for the concentration of the reactant, [A][A], to drop to 6.

Assign the oxidation number for (NH4) 3PO4

When gold is melted and formed in a mold to make a piece of jewelry, what type of change is taking place?