def split_unit_quantity(string):
    """Given a physical quantity as a string, returns a tuple containing the quantity's magnitude and unit, both
    as strings."""
    quantity = ""
    index = 0
    quantity_characters = [str(num) for num in range(10)] + [".", "-", "+"]
    for character in string:
        if character in quantity_characters:
            quantity+= character
            index += 1
        else:
            break
    symbol = string[index:]
    return quantity, symbol