What's the difference between a pure substance and an element

What is the volume of 88 grams of CO2 gas at STP?

How do you know that melting ice is a physical change? Use words to describe what energy is What type of energy causes a rain puddle to disappear on a sunny day? A plumber uses a torch to heat a copper pipe in order to bend it.

Does anyone know a lot about how to: - calculate mass of magnesium metal - calculate the actual yield of magnesium oxide - calculate the theoretical yield of MgO - calculate the percent yield of MgO - determine the percent yield of MgO - determine

What scientific instrument was used to dicover that not all atoms of neon have the same mass?

What is the white solid that forms when methyl salicylate is added to sodium hydroxide?

What is the molality of a solution containing 100 grams of glucose (C6H12O6, molar mass = 180 g/mol) dissolved in 2.5 kg of water? 0.22 m 72 m 7200 m 40 m

A battery is constructed based on the oxidation of magnesium and the reduction of cu2+. the initial concentrations of mg2 + and cu2 + are 1.2*10-4 m and 1.44 m, respectively, in 1.0-liter half-cells. how long can the battery deliver 5.

A buffer solution is made that is 0.417 M in and 0.417 M in. If for is, what is the pH of the buffer solution? pH = Write the net ionic equation for the reaction that occurs when 0.120 mol is added to 1.00 L of the buffer solution.

BaCl2 (aq) + AgNO3 (aq) → Express your answer as a chemical equation. Enter noreaction if no precipitate is formed.

Make a list of physical changes and chemical changes that you observe or see effects of in the school