Input interpretation
metasilicate anion | structure diagram
Result
Draw the Lewis structure of metasilicate anion. Start by drawing the overall structure of the molecule, ignoring potential double and triple bonds: Count the total valence electrons of the oxygen (n_O, val = 6) and silicon (n_Si, val = 4) atoms, including the net charge: 3 n_O, val + n_Si, val - n_charge = 24 Calculate the number of electrons needed to completely fill the valence shells for oxygen (n_O, full = 8) and silicon (n_Si, full = 8): 3 n_O, full + n_Si, full = 32 Subtracting these two numbers shows that 32 - 24 = 8 bonding electrons are needed. Each bond has two electrons, so in addition to the 3 bonds already present in the diagram add 1 bond. To minimize formal charge silicon wants 4 bonds and oxygen wants 2 bonds. Identify the atoms that want additional bonds and the number of electrons remaining on each atom. The net charge has been given to the most electronegative atom, oxygen, in 2 places: Fill in the 1 bond by pairing electrons between adjacent highlighted atoms, noting the formal charges of the atoms. Double bonding silicon to the other highlighted oxygen atoms would result in an equivalent molecule: Answer: | |