What is mixed with natural rubber to obtain vulcanized rubber?

Butanone is a four-carbon compound with the functional group:

Alkynes may be represented by the general formula:

Why are homologous series of carbon compounds so called? Write the chemical formula of two consecutive members of a homologous series and state the part of these compounds that determines their $(i)$ physical properties,and (ii) chemical properties.

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 monomer unit of Teflon?