When does the energy in the H atom get closer

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

Answer asap need by wednesday morning calculate the ph of 0.16m ch3cooh which has ka = 1.74 x 10-5 mol dm-3 best answer will be brainliest

Is water wet? my friends are debating.