Question

lewis dot structure
directions: fill in the lewis dot structure for each of the elements in the table below.
b na sn k i
he something is different about this one... ge kr ga s
sr c li cl as
write the rule: how do you know how many valence electrons an element has?
identify what is incorrect about the following and show the correct lewis structure.
problem what is wrong correct version
n
xe
p

Explanation:

Step1: Determine valence - electron rule

For main - group elements, the number of valence electrons is equal to the group number (for groups 1 - 2, it's the group number; for groups 13 - 18, it's the group number minus 10). For example, elements in group 1 have 1 valence electron, elements in group 17 have 7 valence electrons.

Step2: Analyze 'N' Lewis structure error

Nitrogen (N) is in group 15, so it has 5 valence electrons. In the given structure of N, there are 8 dots around N, which is incorrect. The correct Lewis structure has 5 dots around N.

Step3: Analyze 'Xe' Lewis structure error

Xenon (Xe) is in group 18, so it has 8 valence electrons. In the given structure, the dots are not arranged correctly. The correct Lewis structure has 8 dots arranged around Xe in pairs and singles to represent the valence - electron distribution.

Step4: Analyze 'P' Lewis structure error

Phosphorus (P) is in group 15, so it has 5 valence electrons. In the given structure of P, there are 10 dots around P, which is incorrect. The correct Lewis structure has 5 dots around P.

Answer:

Problem	What is Wrong	Correct Version
:Xe: with incorrect dot - arrangement	Incorrect dot - arrangement for 8 valence electrons	:Xe: with 8 dots arranged properly (2 pairs and 4 singles)
:P: with 10 dots	Incorrect number of valence electrons (should be 5)	:P···

For the first table elements:
B (group 13) has 3 valence electrons, Lewis structure: ·B··
Na (group 1) has 1 valence electron, Lewis structure: Na·
Sn (group 14) has 4 valence electrons, Lewis structure: ·Sn···
K (group 1) has 1 valence electron, Lewis structure: K·
I (group 17) has 7 valence electrons, Lewis structure: :I·····
He (group 18) has 2 valence electrons, Lewis structure: He:
Ge (group 14) has 4 valence electrons, Lewis structure: ·Ge···
Kr (group 18) has 8 valence electrons, Lewis structure: :Kr:
Ga (group 13) has 3 valence electrons, Lewis structure: ·Ga··
S (group 16) has 6 valence electrons, Lewis structure: :S····
Sr (group 2) has 2 valence electrons, Lewis structure: Sr·
C (group 14) has 4 valence electrons, Lewis structure: ·C···
Li (group 1) has 1 valence electron, Lewis structure: Li·
Cl (group 17) has 7 valence electrons, Lewis structure: :Cl·····
As (group 15) has 5 valence electrons, Lewis structure: :As····