How many atoms are present in 3.500 mol of NH3? NEED ANSWER ASAP

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.

Identify the electromagnets with poles that are reversed from the electromagnet shown above

From the options provided for each element below, choose the properties that it may have based on its location in the periodic table fluorine (f): highly reactive nonmetal shiny a conductor