workers disturbing lead-containing paint to establish exposure levels to lead for those workers. The recorded levels are then compared to two different airborne concentrations listed in the OSHA standard: the action limit (AL) and the permissible exposure limit (PEL).
Woozi (ì°ì§) is a South Korean singer. He is a member of the boy group SEVENTEEN and leader of their vocal team unit.
Trends in Properties of Group 17 (VIIA) Elements. 1  All Group 17 (VIIA) elements have 7 valence electrons (7 electrons in the highest energy level). 2  Atomic radius increases down the Group as successive 'electron shells' (energy levels) are filled. As the atomic radius increases and the electron is further from the nucleus it is less attracted to the nucleus (electron is said to be 'shielded'). 2  Melting point and boiling point increase down the Group as the elements become more metallic in nature.