The composition of moist air is given on a molar basis to be 78 percent N2, 20 percent O2, and 2 percent water vapor. Determine the mass fractions of the constituents of air.

Explain how you determine the number of valence electrons that should be used in the dot structure for silicon dioxide and state the shape of the molecule.

Why does chocolate melt faster when crushed?

Which of the following is the best description of the results of a chemical reaction? A new substance with different properties if formed B The substances seem to disappear after dissolving in water.

Neptune's Triton is being pulled closer and closer to the planet as it orbits. What will likely be a result of this gravitational force in the future?

What volume (measured at STP) will 3.75 grams of helium gas occupy?

The correct mathematical expression for finding the molar solubility (s) of sn (oh) 2 is:

18. which bond is most polar? H--F H--Cl H--Br H--I

What kind of reaction is ca (s) + h3po4 (aq) ca3 (po4) 2 (s) + h2 (g)

In the teapot dome scandal, what did the secretary of the interior albert fall lease

A Material made of equal parts is called what? A. Atom, B. Pure substance, C. Mixture