Above question is incomplete. Complete question is attached below
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Correct Answer:
Option D i.e. CH3CH2CH2CH2CH3
Reason:
Isomers are the compounds having same molecular formula, but different structural formula.
The molecular formula of the compound is C5H12
The compound present is question (i.e. 2-methyl butane) and option D (n-pentane) has same molecular formula. Hence, they are isomers.However, compound present in option A, is the same compound provided in question. Hence, it is not an isomer. Compounds reported in option B and C has one carbon atom less and more, respectively as compared to the compound reported in question. Hence, they are also not isomers.
Electronic configuration is given by

- 1s orbital is filled
- 2s orbital is unfilled
So
Answer:
S-type or silaceous asteroids are made up primarily of stony materials and nickel-iron. They inhabit the inner Asteroid Belt. M-type, or metallic, are made up mostly of nickel-iron, and are found in the middle region of the Asteroid Belt
Explanation: