1. A scalar valued function on a vector space with properties analogous to those of the modulus of a complex number; namely: the norm of the zero vector is zero, all other vectors have positive norm, the norm of a scalar times a vector equals the absolute value of the scalar times the norm of the vector, and the norm of a sum is less than or equal to the sum of the norms.

2. For a matrix, the square root of the sum of the squares of the moduli of the matrix entries.

3. See <<absolute value>>

The theoretical mineral composition of a rock expressed in terms of standard mineral molecules as determined by means of chemical analyses.

1. The square of the modulus of a Schrödinger-Pauli wave function, integrated over the space coordinates and summed over the spin coordinates of the particles it describes.

2. The square root of this quantity.