(a) A purchaser from a corporation of its own shares is not liable to the corporation or its creditors with respect to the shares except to pay the full consideration, fixed as provided by law, for which the shares were issued or were to be issued.
(b) Unless otherwise provided in the articles of incorporation, a shareholder of a corporation is not personally liable for the acts or debts of the corporation except that he may become personally liable by reason of his own acts or conduct.