The correct decreasing order of bond angles in the following hydrides is :

Step-by-step solution

According to VSEPR theory, the presence of lone pairs on the central atom causes greater repulsion than bond pairs, compressing the bond angle. CH ₄ has 0 lone pairs ( 109.5^ ), while NH ₃ has 1 lone pair ( 107^ ). Thus, CH ₄ > NH ₃ . Moving down a group (from N to P or O to S), the electronegativity of the central atom decreases and its size increases. This causes the bond pairs to move further away from the central atom, decreasing the bond pair - bond pair repulsion and significantly reducing the bond angle. Thu