def atom_count(data, **params):
    """
    Calculate number of occurrencies of a given atomic element in the data.
    Args:
        data (list): values.
        params (kwargs):
            atom: element for which occurencies are counted.

    Returns the number of occurencies of the atom in the data.
    """
    atom = params['atom']
    counter = sum([elem == atom for elem in data])
    return counter