A scientist to study in a sample of an unknown substance do scientist determine's with the substance is a metalloid with four valence electrons. Which two elements could the unknown be

How many moles of ethyl alcohol, C2H6O, are in a 21.0g sample

Which factor causes a decrease in the rate of dissolution? decreasing the amount of solute increasing the stirring of the solution decreasing the surface area of the solute increasing the temperature of the solvent

A solution is made by dissolving 14.0 g of potassium chloride to a final volume of 78.9 mL solution. what is the weight/weight % or the percent by mass of the solute? (use 1.00 g/mL for the density of water)

An imaginary gas that perfectly obeys all gas laws is called a (n) ___. a) ionic gas b) perfect gas c) ideal gas d) inert gas

A (n) pyramid is a model which represents levels.

A saline solution contains 1.6 % NaCl by mass. How much NaCl is present in 57.2 g of this solution?

During a laboratory experiment you discover that an enzyme-catalyzed reaction has a delta G of - 20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the delta G for the new reaction

What is the molarity of a hydrochloric acid solution prepared by diluting 200.0 ml of 0.500m hcl to a total volume of 1.00 l?

How does a metallic bond differ from an ionic bond

Give two examples of chemical energy being transformed into electrical energy