What is the monomer unit of Teflon?

Which of the following are the heteroatoms present in $CH_{3}-CH_{2}-O-CH_{2}-CH_{2}Cl$?
$(i)$ Oxygen
$(ii)$ Carbon
$(iii)$ Hydrogen
$(iv)$ Chlorine

What is the molecular formula of ethyl alcohol?

In electron dot structure,the valence shell electrons are represented by crosses or dots.
$(a)$ The atomic number of chlorine is $17$. Write its electronic configuration.
$(b)$ Draw the electron dot structure of chlorine molecule $(Cl_2)$.

What is the molecular formula of formalin?

$A$ carboxylic acid (molecular formula $C_{2}H_{4}O_{2}$) reacts with an alcohol in the presence of an acid catalyst to form a compound $'X'$. The alcohol on oxidation with alkaline $KMnO_{4}$ followed by acidification gives the same carboxylic acid $C_{2}H_{4}O_{2}$. Write the name and structure of $(i)$ carboxylic acid,$(ii)$ alcohol,and $(iii)$ the compound $'X'$.