Amolecule of an unsaturated hydrocarbon must have(1) at least on single carbon-carbon bond
(2) at least one multiple carbon-carbon bond
(3) two or more single carbon-carbon bonds
(4) two or more multiple carbon-carbon bonds

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