Why must contact lenses be removed before you enter a chemistry laboratory?

Drag the tiles to the correct locations. each tile can be used more than once, but not all tiles will be used. one or more locations will remain empty. nitrosyl fluoride has the chemical formula nof nitrogen has five valence electrons, oxygen has six, and fluorine has seven. complete the lewis structure for this covalent compound. f n = = = . : : 0 : reset next um. all rights reserved us 2