Element A has 6 valence electrons. Element B has 7 valence electrons. Both atoms must follow the octet rule. In the Lewis structure of AB2, the number of lone pair electrons on the central atom A is:

Two liquids are poured into a beaker. after a few seconds, the beaker becomes warm. which of the following best describes this reaction? a. an exothermic reaction b. a decomposition reaction c. an endothermic reaction d. a single-displacement reaction