[填空题]
Elemental sulfur reacts with fluorine gas to produce a mixture of sulfur fluorides, including $SF_6$ and $SF_4$.
1.The molecular geometry of $SF_6$ can be represented using dash and wedge notation, as shown.
1.State the molecular geometry of SF6$SF_6$,it is .
2.Using dash and wedge notation, draw the molecular geometry of $SF_4$.
3.Explain why the S-F bonds in $SF_4$ are arranged as shown in your answer to (ii).
2.$SF_6$ reacts with water to produce sulfur trioxide($SO_3$).
$SO_3$ has multiple resonance structures. One resonance structure A is shown.
1.Calculate the formal charge of the S atom in A, the formal charge is .
2.In a second resonance structure, B, the S atom obey the octet rule.
S atom obeys the octet rule.Draw the second structure of B, including all non-zero formal charges and non-bonding electron pairs.
3.State which resonance structure is preferred, giving a reason for your answer.
