PLEASE HELP! Which statement below describes the properties of a penny on Earth compared to a penny on Mars?

- The density of the penny would change because the mass would change.

- The volume of the penny would change because the weight would change.

- The mass of the penny would change but the density would remain the same.

- The weight of the penny would change but the mass would remain the same.

Gabriel is at a stage where his body is changing physically; he is growing facial hair and building muscle. he is also just starting to make sperm. what is most likely gabriel’s age? 5 12 17 21

What makes the results of a scientific experiment accurate? a) having multiple trials b) lacking any supporting data c) working in a lab d) using a hypothesis that is always true

To answer this question, researchers studied populations of the dusky salamander (desmognathus ochrophaeus) living on different mountain ranges in the southern appalachian mountains. the researchers tested the reproductive isolation of pairs of salamander populations by leaving one male and one female together and later checking the females for the presence of sperm. four mating combinations were tested for each pair of populations (a and b)—two within the same population (female a with male a and female b with male b) and two between populations (female a with male b and female b with male a). the proportion of successful matings for each mating combination was measured. for example, when all the matings of a particular combination were successful, the researchers gave it a value of 1; when none of the matings were successful, they gave it a value of 0. then the researchers calculated an index of reproductive isolation that ranged from 0 (no isolation) to 2 (full isolation). the reproductive isolation value for two populations is the sum of the proportion of successful matings of each type within populations (aa + bb) minus the sum of the proportion of successful matings of each type between populations (ab + ba). the table provides data for the geographic distances and reproductive isolation values for 27 pairs of dusky salamander populations.