ALOT OF POINTS plus marking people as brainlist

Pentane with molecular formula c5h12, exists in three isomeric forms. one shows linear carbon chains, another has one -ch3 groups present on the third carbon atom, and the third has two -ch3 groups present on the second carbon atom. what types of isomers are these? a. geometric isomers b. structural isomers c. halotropic isomers

Which of these is not a nucleotide base found in dna?

How can we use spectral lines of light coming from the superclusters to identify which is receding from earth at the slowest rate.