Question

how many unshared electrons (dots) are in a correctly drawn lewis structure for ch₂o?

Explanation:

Step1: Determine the valence electrons

Carbon ($C$) has $4$ valence electrons, hydrogen ($H$) has $1$ valence electron, and oxygen ($O$) has $6$ valence electrons. For $CH_{2}O$, the total number of valence electrons is $4+(2\times1)+6 = 12$.

Step2: Draw the Lewis structure

Carbon is the central atom. Carbon forms a double - bond with oxygen ($C = O$) (which uses $4$ electrons for the bond) and single - bonds with two hydrogen atoms ($C - H$, each uses $2$ electrons). The bonds account for $(2\times2)+(2\times1)=6$ electrons.

Step3: Calculate unshared electrons

Using the formula: unshared electrons = total valence electrons - electrons in bonds. So, unshared electrons $=12 - 6=6$.

Answer:

$6$