1. what is the formula of a compound that contains na+ and po4 3- ions? a. na3p b. napo4 c. na3po4 d. na3po3 e. na2po3 2. which of the following substances contains a nonpolar covalent bond? a. h2o b. n2 c. nacl d. nh3 e. mgf2 3. the main type of attractive forces between molecules of ammonia (nh3) are a. dipole-dipole attractions b. hydrogen bonds c. dispersion forces d. ionic bonds e. polar covalent 4. the carbon tetrachloride molecule, ccl4, has the shape of a a. circle b. cube c. square d. tetrahedron e. sphere 5. which formula shows the proper use of parentheses? a. ca(f)2 b. ca(so4) c. (nh4)3(po4) d. ca(no3)2 e. none of the above 6. which among the following elements does not exist as a diatomic molecule in nature? a. hydrogen b. nitrogen c. fluorine d. neon e. na