What is the bond angle in ammonia molecule?

109028' 1080 1070 104.50

1070

The bond angle for a standard tetrahedral geometry is 109.5°. But the ammonia molecule contains a lone electron pair on nitrogen. As it is closer to the N atom than the other orbitals, it creates a repulsive effect and pushes the Hydrogen atoms close to each other, thus reducing the bond angle to 107°.