��
� ��	http://global-colleges.com/vb/%D8%A7%D9%84%D9%83%D9%8A%D9%85%D9%8A%D8%A7%D8%A1-chemistry/
� ��	416
� �� 1
� �� 2
� ��	�� 0 �� 0 ��
� ��	�� - �� - ��
� ��
� ��