Question

Which of the elements shape oa very similar to NH3

Answer 1

Methane has a tetrahedral structure with Carbon at the center and Hydrogen atoms at the four vertices. Bond angles are 109.5 degree. In case of ammonia, Nitrogen atom is at the center and three Hydrogen atoms are at three vertices. The lone pair on N points to the fourth vertice.
U should check valence shell electron pair repulsion theory (VSEPR theory)
Atoms try to attain stability by arranging as far as possible maintaining specific angles.
In case of NH3 , H3O+ they are AB3 type which has pyramidal structure



But NH4+ and CH4 are AB4 type which has tetrahedral shape