import math


def nagle(nvalence: int, polarizability: float) -> float:
    """
    Calculate the electronegativity of an atom according to the definition
    of Nagle

    Args:
        nvalence: number of valence electrons
        polarizability: dipole polarizability
    """

    return math.pow(nvalence / polarizability, 1.0 / 3.0)