A student is trying to determine the identity of some pieces of an unknown substance by finding their density. He finds the mass of a weighing boat to
be 2.69 g and the mass of the unknown pieces, including the weighing
boat, to be 18.01 g. To find the volume of the pieces, he measured out 25.7
mL of water in a graduated cylinder and then added the pieces to find a
new volume of 32.3 ml. What is the identity of the substance?
Density
2.16
Mineral
Halite
2.32
Gypsum
Quartz
2.65
2.72
Calcite
3.18
Fluorite
O halite
O quartz
O
O gypsum
fluorite

When a comet collides with earth, it adds material to our planet and causes great damage. therefore, a collision like this is a a. destructive force b. constructive force c. geologic process and event d. constructive and destructive force

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

How can carbon move from "land" to bodies of water? describe the way human impact has lead to increased levels of co2 in the atmosphere.