6. Atoms can gain or lose electrons to become chemically stable. An atom is
stable when it gains valence electrons to reach a total of 8 valence
electrons, or loses valence electrons to achieve an empty outer shell (0
valence electrons). Based on this information, identify two elements that
could form a chemical bond by one atom losing electrons and the other
atom gaining these electrons.

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.

Which statement describes covalent bases? they have hydroxide ions. they produce hydrogen ions. they are often amines. they are named the same as ionic compounds.

The climate of the continental united states is generally 1. tropical 2. temperate 3. arctic 4. highland