$A$ compound whose molecules are superimposable on their mirror images even though they contain an asymmetric carbon atom is called:

Given below are two statements :
Statement $(I) :$ $CH_3CH=CHCH_3$ and $cyclobutane$ are isomeric compounds.
Statement $(II) :$ $CH_3CH_2CH_2CH_2NH_2$ and $(CH_3CH_2)_2NH$ are functional group isomers.
In the light of the above statements,choose the correct answer from the options given below :

The number of isomers of $C_4H_{10}$ is:

Compounds with the same molecular formula but differing in their structures are called structural isomers. What type of structural isomerism is shown by $CH_3-S-CH_2-CH_2-CH_3$ and $CH_3-S-CH(CH_3)_2$?

Identify the pairs of compounds that represent position isomerism:
$(I)$ $CH_3-CH_2-CH_2-CH_2-OH$
$(II)$ $CH_3-CH_2-CH(OH)-CH_3$
$(III)$ $CH_3-C(CH_3)(OH)-CH_3$
$(IV)$ $CH_3-CH(CH_3)-CH_2-OH$
$(V)$ $CH_3-CH_2-O-CH_2-CH_3$
$(VI)$ $CH_3-O-CH_2-CH_2-CH_3$
$(VII)$ $CH_3-O-CH(CH_3)-CH_3$

What is isomerism? Explain with a suitable example.