The magnetic moment of a nucleon is sometimes expressed in terms of its g -factor, a dimensionless scalar. The convention defining the g -factor for composite particles, such as the neutron or proton, is μ μ = g μ μ N ℏ ℏ I , where μ is the intrinsic magnetic moment, I is the spin angular momentum, and g is the effective g -factor. While the g -factor is dimensionless, for composite particles it is defined relative to the nuclear magneton. For the neutron, I is ⁠ 1 / 2 ⁠ ħ, so the neutron's g -factor is g n = −3.826 085 52 (90), ‍ while the proton's g-factor is g p = 5.585 694 6893 (16). ‍