Draw all the no-bond resonance structures of isopropyl carbocation.

Which is the essential element in all organic compounds?

Which classes of organic compounds are often used in our daily diet?

Draw the structural formula of ethane.

Draw the electron-dot structure of propane.

(i) Observe the compounds $\left(\mathrm{a}\right)$ to $\left(\mathrm{e}\right)$

(ii) Identify the compounds those contain a ring of carbon atoms only.

(iii) Identify the compounds in which ring contains at least one atom other than carbon.