Mary roller skates 18 miles in 1 1/2 hours what is her average speed in miles per hour

If a gaseous mixture is made by combining 3.78 g Ar and 3.27 g Kr in an evacuated 2.50 L container at 25.0 ∘ C, what are the partial pressures of each gas, P Ar and P Kr, and what is the total pressure, P total, exerted by the gaseous mixture?

You need to make an aqueous solution of 0.207 M calcium acetate for an experiment in lab, using a 300 mL volumetric flask. How much solid calcium acetate should you add?

Based on the standard free energies of formation, which of the following reactions represent a feasible way to synthesize the product? A. 2C (s) + H2 (g) ? C2H2 (g); ? G? f=209.2 kJ/mol B. C (s) + O2 (g) ? CO2 (g); ? G? f=?394.4 kJ/mol C.

V. T2 = V2T, is an expression of Boyle's Law Dalton's Law The Ideal Gas Law Charles' Law

Is the periodic table of the elements all of the atoms known to exist?

Name the element that has atoms with the same electronic structure as sulfur ion

The mass of a 2.0 centimeter sample of a substance is 3.2 grams. Calculate the density of the substance

The aromatic amino acids are synthesized in humans by a pathway beginning with reaction of indole with serine. synthesized in bacteria in a pathway shared by all three, up to the production of the intermediate chorismate.

Which element is a liquid at 25 celsius degrees and 1.0 atm? (A) bromine (B) krypton (C) phosphorus (D) xenon

Why do atoms receive a positive or negative charge when they give or take electrons? Include the nucleus in your explanation.