90 % of marine organisms and 70% of land organisms died off due to environmental and/or climate changes during the paleozoic era. true or false

Other than earth, is also known to have magnetic pole reversal? a: venus b: mars c: earths moon d: the sun

Explain the significance of thesaurus geographicus

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