Question

decide whether these proposed lewis structures are reasonable.
proposed lewis structure is the proposed lewis structure reasonable?
:o - c - o:
yes.
no, it has the wrong number of valence electrons.
the correct number is:
no, it has the right number of valence electrons but doesnt satisfy the octet rule.
the symbols of the problem atoms are:
h - h - o
yes.
no, it has the wrong number of valence electrons.
the correct number is:
no, it has the right number of valence electrons but doesnt satisfy the octet rule.
the symbols of the problem atoms are:
h - br:
yes.
no, it has the wrong number of valence electrons.
the correct number is:
no, it has the right number of valence electrons but doesnt satisfy the octet rule.
the symbols of the problem atoms are:

• if two or more atoms of the same element dont satisfy the octet rule, just enter the chemical symbol as many times as necessary. for example, if two oxygen atoms dont satisfy the octet rule, enter o o.

Explanation:

Step1: Calculate valence - electrons for CO₂

Carbon has 4 valence electrons and oxygen has 6 valence electrons. For CO₂ ($CO_2$), the total number of valence electrons is $4 + 2\times6=16$. The given structure :O - C - O: has the correct number of valence - electrons and satisfies the octet rule for all atoms.

Step2: Calculate valence - electrons for H₂O

Hydrogen has 1 valence electron and oxygen has 6 valence electrons. For H₂O ($H_2O$), the total number of valence electrons is $2\times1 + 6=8$. The structure H - H - O: is incorrect as the hydrogen atoms are bonded to each other instead of the oxygen atom. The correct structure should have hydrogen atoms bonded to the oxygen atom. The given structure has the wrong number of bonding arrangements. Also, the number of valence electrons in the given structure is wrong. The correct number of valence electrons for H₂O is 8.

Step3: Calculate valence - electrons for HBr

Hydrogen has 1 valence electron and bromine has 7 valence electrons. For HBr ($HBr$), the total number of valence electrons is $1+7 = 8$. The structure H - Br: has the correct number of valence electrons and satisfies the octet rule for bromine and the duet rule for hydrogen.

Answer:

1. Yes.
2. No, it has the wrong number of valence electrons. The correct number is: 8
3. Yes.