In a molecule of calcium sulfide, calcium has two valence electron bonds, and a sulfur atom has six valence electrons. How many lone pairs of electrons are present in the Lewis structure of calcium sulfide? A. one
B. two
C. three
D. four
E. none

Which of the following is not true about the atomic model of substances?

Which statement best describes isomers? a. isomers are alcohols that have the same functional group. b. isomers have at least one carbon-carbon double bond. c. isomers have the same molecular formula but different structural properties.

What changes occur in the reaction indicated by the equation? check all that apply. the hydrogen nucleus loses protons. the oxygen nucleus gains protons. the bond in h2 is broken, and new bonds are formed between hydrogen and oxygen atoms. each electron associated with a hydrogen atom is shared with an oxygen atom.