what volume of 0.250M nitric acid is required to neutralize a solution prepared by dissolving 17.5 g g

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

Can someone me with 3 and 4 plz. this is for masteries test.

The arrangement of particles is most ordered in a sample of