Which of the following is true about density? it changes constantly
it cannot be used to identify a substance
it stays the same no matter how much of the substance that you have
it changes depending on how much of the substance that you have

The table shows dates and appearance of index fossils. which rock layers can be dated most precisely? a) a layer containing both a fossil 4 and a fossil 3 b) a layer containing both a fossil 2 and a fossil 3 c) a layer containing both a fossil 1 and a fossil 4 d) a layer containing both a fossil 1 and a fossil 2

Johnny rode his bike to a friend's house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was not able to play. what was his displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point

In the respiration-photosynthesis cycle shown above, what are the products of cellular respiration that belong in box 2?