Question

directions: each set of lettered choices below refers to the numbered statements immediately following it. select the one lettered choice that best fits the statement. a choice may be used once, more than once, or not at all. the question refers to the following species. (a) h₂o (b) nh₃ (c) bh₃ (d) ch₄ 9 has two lone pairs of electrons

Explanation:

In a water ($H_2O$) molecule, the oxygen atom has two lone - pairs of electrons. Oxygen has 6 valence electrons. It forms two bonds with hydrogen atoms, leaving two non - bonding pairs of electrons. In ammonia ($NH_3$), nitrogen has one lone - pair. Boron trihydride ($BH_3$) has no lone - pairs on the central boron atom as boron has 3 valence electrons and forms three bonds with hydrogen atoms. Methane ($CH_4$) has no lone - pairs on the central carbon atom as carbon has 4 valence electrons and forms four bonds with hydrogen atoms.

Answer:

A. $H_2O$