11. Ionic compounds that dissolve in water conduct electricity because they break into ions that move freely.
12. Solid metals are good conductors of heat and electricity.
13. Molecular compounds that dissolve in water do not conduct electricity because no charged particles are present.
14. Because the electrons in a molecule of hydrogen fluoride (HF) are more strongly pulled toward the fluorine atom, the molecule is polar.
15. A metal crystal consists of positively charged metal ions embedded in a "sea" of freely moving valence electrons.
16. The properties of solid metals can be explained by the structure of and the bonding among the metal atoms. = True
17. Orderly crystal shapes, high melting points, and electrical conductivity, when dissolved in water, are properties of ionic compounds. = True
18. When electrons are transferred between two atoms, a covalent bond is formed. = False (When electrons are shared between two atoms, a covalent bond is formed.)
19. A low melting point is one property of molecular compounds. = True
20. A nonpolar bond is formed when two atoms share electrons unequally. = False (a polar bond is formed)
