How many moles of helium are inside a 7.3 L party balloon at STP?

There are 6.022, 104 atoms of hg in 1 mole of hg the number of atoms in 45 moles of hg can be found by multiplying 4.5 by 6.022, 102 which is the number of atoms in 4.5 moles of hg, correctly written in scientific notation with the correct number of significant figures? 0 21,109 0 21,100 271, 1024 27.099, 100 mark this and retum save and exit submit

At 20°c, a sample of h2o liquid and a sample of co2 gas each have the same average kinetic energy. why is one a liquid and the other a gas at this temperature?

Do polar molecules have ionic bonds?