PLS HELPPP How many moles of oxygen atoms (not molecules) are present in 6.41×1025 molecules of dinitrogen pentoxide (N2O5)? 1. 532 mol 2. 106 mol 3. 32 × 1025 mol 4. 266 mol

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.

You open a can of soda at room temperature and hear a hiss. which of the following factors has changed inside the container? a.) atmospheric pressure b.) temperature of gas c.) type of gas d.) amount of gas

Calculate the ph of a .10m nh4cl solution. the kb value for nh3 is 1.8×10^-5