The total amount of energy that remains in the system always even in an ideal system with no friction or air resistance.
a) increases
b) decreases
c) stays the same
d) it depends on the system

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.

Write a hypothesis that answers the lesson question, “while observing a chemical reaction, how can you tell which reactant is limiting? ” hypothesis: if a substance is the limiting reactant, then . . because . .

What material does not melt at any temperature