What is a change in matter that results in a change in its identity and properties? *

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.

|using the periodic tablewarm-upuse the periodic table in the tools bar to answer the following questions. what elemental classification does oxygen belongto? done

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?