Why potassium bromide is KBr but pitassium oxide is K2O

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

How many moles of oxygen gas are produced from the decomposition of six moles of potassium

How many grams are in 68.2 molecules of br2?