What was johann dobereiners contribution to the development of the periodic table

What mass of ammonia will exert the same pressure as 12.8 mg of hydrogen sulfide (H2S) in the same container under the same conditions?

If you had a substance that water will not dissolve, then which of the following compounds would you choose to dissolve this substance? A. Vegetable oil B. Any polar substance C. Any ionic substance. D. None of the above will work.

An average sample of coal contains 3.0% sulfur by mass. calculate the moles of sulfur present in 2.40 ' 103 kg of coal.

When a solute molecule is solvated, is energy released or absorbed?

3. Potassium chlorate, KC103, decomposes when heated to produce potassium chloride and oxygen gas. If 6.50 grams of KClO3 were heated in a test tube, how many grams of oxygen gas should be given off?

The three major groups p On the periodic table are the

Which of the following has the greatest mass, in grams? a. 1 atom of lead (Pb) b. 0.5 mol copper (Cu) atoms c. 0.3 mol gold (Au) atoms d. 25 atoms of mercury (Hg)

Which one is not a sedimentery rock a.) sandstone b.) limestone c.) quartz d. (coal

Which group is more reactive than the alkaline earth metals?

Why do you not want any of the water on the outside of the test tube to drip off into the calorimeter?