Final answer:
The Lewis structures for the given molecules and ions are as follows: SO3, NO2-, ClO4-, and BF3.
Step-by-step explanation:
Here are the Lewis structures for each of the molecules and ions:
a) SO3: Each S atom is bonded to three O atoms, and there is a double bond between one S atom and one O atom. The Lewis structure for SO3 is:
O = S = O
O
b) NO2-: There is a single bond between the N atom and one O atom, and a double bond between the N atom and the other O atom. The Lewis structure for NO2- is:
O - N = O
c) ClO4-: The Cl atom is bonded to four O atoms, and there is a single bond between each Cl atom and each O atom. The Lewis structure for ClO4- is:
O - Cl - O
O
O
O
d) BF3: Each B atom is bonded to three F atoms, and there are no lone pairs on the B atoms. The Lewis structure for BF3 is:
F
B - F - F
F