Which statement is not true about elements in group 16?

a. they need two electrons to complete their octet.
b. they have an oxidation number of 2-
c. they have an oxidation number of 2+
d. the have six valence electrons.

10-14. (a) when 100.0 ml of weak acid ha were titrated with 0.093 81 m naoh, 27.63 ml were required to reach the equivalence point. find the molarity of ha. (b) what is the formal concentration of a- at the equivalence point? (c) the ph at the equivalence point was 10.99. find pk. for ha. (d) what was the ph when only 19.47 ml of naoh had been added?

Which best describes why nh4+ can form an ionic bond with ci-?

Give the orbital configuration of the phosphorus (p) atom.