Why is the strength of a hydrogen bond greater than that of a dipole interaction force when hydrogen bonds with other molecules? A. When bonded, hydrogen's small size and positively charged exposed nucleus lead to strong attraction between hydrogen and electronegative molecules.

B. Hydrogen is larger than the electronegative atoms it bonds with.

C. Hydrogen has three electron shells that protect its nucleus.

D. When hydrogen combines with other atoms, its electrons are strongly drawn toward the nucleus.

The earth's moon is unusually large. two popular theories of the moon's origin include the "sister world" hypothesis, which states that the moon formed from the same materials as the earth, near enough to the earth that they fell into orbit around each other. a second theory is the "capture" hypothesis, in which the moon formed elsewhere in the solar system, and the earth's gravity pulled it into its orbit. studies of what the moon is made of indicate that some of its materials had to come from the earth or from the same area of the solar system where the earth had formed. at the same time, the moon does not contain much of the material that makes up the earth's core, so the moon could not have formed from the same materials as the earth. how do the two facts above affect the described theories of the moon's origin? a. they show that scientists will never agree on where the moon came from. b. they show that more experiments on moon formation need to be done. c. they show that no theory accounts for the existence of the moon. d. they show that neither theory is complete and entirely correct.

Consider the following system at equilibrium. caco3(s) ca2+(aq) + co32–(aq) the addition of which compound will cause a shift in equilibrium because of a common ion effect? ccl4 co2 cuso4 na2co3

Which of the following is always a reactant in a combustion reaction? oxygen nitrogen hydrogen carbon