Lewis dot structure for alf63-

Answer 1

alf63- sounds like a space creature and has no meaning in chemistry. Do you mean AlF63-?
This is an unusual structure. Since there's only one Al, that goes in the middle. Each of the Fluorines needs only one more electron (which each does through forming a single covalent bond), so draw each of the fluorines around the Al and draw a single line between the Al and each F to indicate a single bond.
Now that the skeleton's in place, make sure the electrons add up correctly. We'll add up all the valence electrons available to use (from Al and the 6 F, AND the 3 that make the -3 charge), and then we'll subtract what electrons we used to make the skeleton. here goes:
Al has 3 valence e-, and each F has 7 valence e-. 3 + 7×6 = 45. then we add the 3 e- for the -3 charge: 45+3 = 48 total e- to use in our structure. Now we count what we used up. Each F has 3 lone pairs of e- around it (wants a full octet, makes only one bond, this leaves 6 e- unbonded), so that accounts for 6×(2×3) electrons -- that's 6 Fluorines, and 2 electrons in each of 3 lone pairs around each flourine. this is 36 electrons used up from our 48 total. So we have 12 more to account for. For each flourine, you drew a single bond between the Flourine and the Al. a single bond is made of 2 electrons, so in total this is 6×2 electrons -- 6 Al-F bonds, and 2 electrons per bond. This is 12 electrons, so we've accounted for all 48 available electrons for our structure.

The correct structure has Al in the center with 6 Flourines single-bonded to it, and the whole structure carries a -3 charge.

Answer 2

The Lewis dot structure for AlF6^3- has one aluminum (Al) atom in the center, with six fluorine (F) atoms surrounding it. Each F atom is connected to Al via a single bond, with three lone pairs around each F atom. The overall charge of the ion is -3 due to the three extra electrons.