Ans: Carbon dioxide (CO₂) consists of one carbon atom and two oxygen atoms. The electron dot structure (also known as the Lewis structure) represents the valence electrons of atoms within a molecule.
- Carbon (C) has 4 valence electrons.
- Oxygen (O) has 6 valence electrons.
- Total for CO₂ = 4 (for C) + 6*2 (for 2 O) = 4 + 12 = 16 valence electrons.
Carbon is the central atom because it is less electronegative than oxygen.
The basic structure is O=C=O.
MCQs Based on the above question
Question 1:
Which of the following represents the total number of valence electrons in a CO₂ molecule?
a) 12
b) 16
c) 20
d) 24
Answer: b) 16
Question 2: In the Lewis structure of CO₂, what type of bonds are formed between the carbon and oxygen atoms?
a) Single bonds
b) Double bonds
c) Triple bonds
d) Ionic bonds
Answer: b) Double bonds
Question 3: Which atom is the central atom in the CO₂ molecule, and why?
a) Oxygen, because it is more electronegative
b) Carbon, because it is less electronegative
c) Oxygen, because it has more valence electrons
d) Carbon, because it has more valence electrons
Answer: b) Carbon, because it is less electronegative
Question 4: How many lone pairs of electrons are present on each oxygen atom in the CO₂ molecule?
a) 0
b) 1
c) 2
d) 4
Answer: c) 2