The correct answer is: Both A and R are true, but R is not the correct explanation of A.
Explanation:
Isomers are compounds that have the same molecular formula but different structural formulas. This means that they have the same number and type of atoms, but the atoms are arranged differently in space.
For example, ethane and ethene are both isomers of C2H6. Ethane has a molecular formula of C2H6 and a structural formula of CH3CH3. Ethene has a molecular formula of C2H6 and a structural formula of CH2CH2.
In ethane, the carbon atoms are bonded to each other by a single bond. In ethene, the carbon atoms are bonded to each other by a double bond.
The double bond in ethene makes it a different compound than ethane. Ethene is more reactive than ethane because the double bond is a site of high electron density.
Option A: Both A and R are true and R is the correct explanation of A.
This option is incorrect because R is not the correct explanation of A. The fact that isomers have different arrangements of their constituent atoms in space does not explain why they have different properties.
Option B: Both A and R are true, but R is not the correct explanation of A.
This option is correct because A is true and R is true, but R is not the correct explanation of A.
Option C: A is true, but R is false.
This option is incorrect because R is true.
Option D: A is false, but R is true.
This option is incorrect because A is true.