What is the density of an object with mass 80 kg and volume 05 cubic meters

You may expect bonds between two atoms which each have n covalent lonic metallic hydrogen

How many moles of magnesium is 3.01 x10^22 atoms of magnesium?

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