Hydrogen azide, HN₃, and its salts (metal azides) are unstable substances used in detonators for high explosives. Sodium azide, NaN₃, is used in air-bag safety systems in automobiles. A reference source lists the following data for HN₃. (The subscripts a, b, and c distinguish the three N atoms from one another.) Bond lengths: N_a—N_b = 124 pm; N_b—N_c = 113 pm. Bond angles: H—N_a—N_b = 112.7°; N_a—N_b—Nc = 180°.

Write two contributing structures to the resonance hybrid for HN₃, and describe a plausible hybridization and bonding scheme for each structure.