Percent yield =(Experimental)/(Theoretical) x 100 = 2.55 g/ 2.78 g x 100 = 91.7%
<span>Selenium has 6 valence electrons, shares four of them with the four F atoms and has a pair of electrons left over, so has l0 electrons in its outer energy level. Choice A</span>
C. horizontal
please rank brainliest if possible :)
<span> I would guess that calcium (Ca), of all the group 2 elements, is most like magnesium (Mg), because it has the most similar size (atomic and ionic radii) to Mg. </span>