The liquid pentafluorobenzene has a density of 1.51 g/ml at 20 °c. if a sample of this liquid at 20 °c has a volume of 2.08 l, how many grams of liquid are there in the sample?

6what is the importance of water on earth? a) it keeps the top layer of the geosphere cool b) it allows life to exist c) it provides ice at the poles d) it creates earth's blue color from space

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size

The identities of substances are the same before and after which type of change