If E is the symbol for an element, which two of the following symbols represent isotopes of the same element?

Becquerel expected to find ( he developed the photographic plate that had sun-exposed minerals on top of it. becquerel expected to find ( he developed the photographic plate that had been in the closed drawer.

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

Match the mixture with the substance// i really need on this guys (it’s a pic btw)