Lewis structure of NH₄⁺
8 valence electrons. Four N-H single bonds, with no lone pair on N.
Lewis structure
8 valence electronsFormal charges: N +1
Why this shape
- N has 5 valence electrons. In the Lewis structure it makes four single bonds to H and keeps no lone pair, which leaves it a formal charge of +1.
- Steric number = four sigma bonds + no lone pairs = 4, so N is sp³ hybridised.
- Four electron pairs point to the corners of a tetrahedron (tetrahedral electron geometry). With no lone pairs the atoms take the same shape: tetrahedral.
- All the bond pairs repel each other equally, so the angle is the ideal 109.5°.
- NH₄⁺ is an ion with an overall charge of +1, so it is not described as polar or non-polar.
How to draw it
- Count the valence electrons: N 5 + 4 × H 1 − 1 for the ⁺ charge = 8 valence electrons, 4 pairs.
- Put N in the middle and join it to the four outer atoms with single bonds.
- Give each outer atom lone pairs until it has an octet (H needs only two electrons), then put any electrons left over on the central atom.
- Result: four N-H single bonds, with no lone pair on N.
- Formal charge = valence electrons − lone pair electrons − number of bonds. Here: N +1.
Class 11, Chapter 4 Chemical Bonding and Molecular Structure.
Lewis structure of NH4+: quick answers
How many valence electrons are in NH4+?
N 5 + 4 × H 1 − 1 for the ⁺ charge = 8 valence electrons, 4 pairs.
What are the formal charges in the Lewis structure of NH4+?
N +1; every other atom is zero. Formal charge = valence electrons - lone pair electrons - number of bonds.
How many lone pairs are in the Lewis structure of NH4+?
0 in all, none on the central N.