Which of the following choices represents a balanced chemical equation? ca3(po4)2 + 6sio2 → p4o10 + 3casio3 2ca3(po4)2 + 6sio2 → p4o10 + 6casio3 2ca3(po4)2 + 3sio2 → 2p4o10 + 2casio3 3ca3(po4)2 + 2sio2 → p4o10 + 4casio3

One mole of zinc has a mass of 65.4 grams. approximately how many atoms of zinc are present in one mole of zinc? 32 × 1023 atoms 6 × 1023 atoms 66 atoms 65 atoms

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.

The rules of engagement (roe) working group is often used to (select all that apply.)