Radical chlorination of pentane is a poor way to prepare 1-chloropentane, but radical chlorination of neopentane, (ch3)4c, is a good way to prepare neopentyl chloride, (ch3)3cch2cl. why?

Radical chlorination is not as selective as radical bromination. the rate in which it reacts with primary, secondary or tertiary hydrogens is not that great of a difference. 

So, in pentane, CH3CH2CH2CH2CH3, by the reaction with Cl2, the chlorine group can attach to any of the carbons which would form many isomers and not specifically 1-=chloropentane. In neopentane, (CH3)4C, it is different. each of the H atoms is equivalent. So no matter which one be substituted, only one product, (CH3)CCH2Cl, can be prepared.