In the $3D$ representation of an organic molecule,which model indicates atomic size?

Match List-$I$ with List-$II$.
| List-$I$ | List-$II$ |
| :--- | :--- |
| $(A)$ Tetrahydrofuran | $(I)$ Spiro compound |
| $(B)$ Bicyclo[$1.1$.$0$]butane derivative | $(II)$ Aromatic compound |
| $(C)$ Spiro[$2.2$]pentane derivative | $(III)$ Non-planar heterocyclic compound |
| $(D)$ Furan | $(IV)$ Bicyclo compound |
Choose the correct answer from the options given below.

How many double bond equivalents (degree of unsaturation) does amoxycillin possess?

Write the importance of organic chemistry.

Among the compounds
$(i)$ $HC \equiv C-COOH$
$(ii)$ $CH_2=CH-COOH$
$(iii)$ $CH_3-CH_2-COOH$ and
$(iv)$ $CH_3-CH_2-OH$
The correct order of acid strength is

What is the molar mass of the third member of a homologous series if the molar mass of the first member is $46 \ g \ mol^{-1}$?