Was the mass of 20 pennies equal to 20 times the mass of one penny? Explain.

The organism shown is a free-living one that is anchored to the bottom of ponds and streams during one stage of its life cycle what is the common name for the group to which this organism belong

The diagram below shows a cell placed in a solution. a cell is shown placed inside a beaker. it is labeled cell. the solution inside the beaker is labeled 40% salt solution and the solution inside the cell is labeled 20% salt solution. only water is allowed to move in and out of the cell. what will most likely happen to the cell? it will expand as water moves out of it. it will shrink as water moves out of it. it will expand as water moves into it. it will shrink as water moves into it.

Mercury turns to a vapor at 629.88 k. how much heat is lost when 75.0 g of mercury vapor at 650 k condenses to a liquid at 297 k?