Two students made the Lewis dot diagrams of H2O. The diagrams are as shown.

Question

Two visual diagrams of an H two O molecule are shown. Student As diagram on the left has oxygen at the center and connects with two hydrogen atoms by way of straight lines. There are two pairs of dots above the oxygen atom. Student Bs diagram is identical except it has one pair of dots and instead of lines, and it has an arrow between the oxygen and each hydrogen.

Which student drew the correct Lewis dot diagram?

Only Student A
Only Student B
Both Student A and Student B
Neither Student A nor Student B

Answer 1

The correct answer is only Student A.

Student A's diagram accurately represents the Lewis dot structure for H₂O (water). In this structure, the oxygen atom (O) is the central atom and is connected to two hydrogen atoms (H) through covalent bonds, which is appropriate to represent with straight lines. Additionally, the two pairs of dots above the oxygen represent the lone pairs of electrons on the oxygen atom.

Student B's diagram, which uses arrows instead of lines for the bonds, is not a standard representation for Lewis dot structures. Arrows are often used to indicate the direction of electron donation or flow in reaction mechanisms or resonance, but they do not represent the covalent bonding in this context accurately.

Therefore, the correct Lewis dot diagram for a water molecule is drawn by only Student A.