In what directions must energy be added to cause the indicated phase change? a) solid to gas, gas to liquid, liquid to solid b) solid to liquid, gas to liquid, solid to gas c) solid to liquid, liquid to gas, gas to solid d) solid to liquid, liquid to gas, solid to gas

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.

Idon't really understand this can you me and show your work.☺☺[ chemistry b] subject [ electron transfer in lonic bonds]grade( 12)

What is the percentage of hydrogen in c2h4